Hi Terry, I have an A1 Elite and have loved and used it for the last 8 years. I wouldn't trade it for anything!!
I can run any threads I want. Yes I do change the tensions, both top and bobbin. Don't let any sales person tell you "you don't need to change the tension with our machine" Or worse "Use only XYZ brand and you'll be fine". Neither is true!
I will say when I was a newbie, I had a bit of trouble running specialty threads, so some of it is learning curve. But once you learn the LA, and yours in particular, and learn how to move smoothly and consistently, you should be able to run any thread.
Tension is a balancing act. Different threads have different weights, plys, slickness, etc. It all comes into play. The A1 comes with two tensioners, so you can choose which one you like to use. I prefer the disc tensioner (like the Featherweight has... two metal discs that you run the thread thru) but it also has a rotary tensioner (felt discs that turn with the thread). (You don't use both at once...LOL)
A TOWA is worth it's weight in gold!! I always test every bobbin. I know when settings I like for which threads I am using. That makes tension setting a breeze!
Skipped stitches should not happen on any LA. If the LA is skipping, and there is an empty hole left in the fabric, that means the timing could be off. The needle is not picking up the bobbin thread to make the loop of the stitch. Sometimes, changing to one size larger needle will solve it. Sometimes, turning the needle a tiny bit to the right will solve it. Sometimes, you have to change the timing. I almost never get skipped stitches on my A1. She's timed perfectly and holds the timing well. In fact, I have never retimed her in 8 years!!
Thread breakage can be caused by many things. It can happen on any longarm. Thread can get brittle or weak, needle size can be too small, a burr on the thread path can snag the thread, a lumpy seam can cause it, even the fabric and batting can wreak havoc with your thread. You learn as you quilt what threads work best for what situations. Of course, constant breakage is not good and if it happen with all threads, all the time, then a call to your dealer is in order. I rarely have thread breakage with my A1 but I can't say never. I just quilted a lap quilt yesterday using Signature 100 % cotton and had one thread break total. Not really sure why, but sometimes it does happen. The quilt before had no breaks. Using good quality thread is important too. Some longarmers like to use the cheapest thread they can find (often a two ply from the big box stores made for sergers) and I will say, that is not a good strategy. LA sewing is much more abrasive on the thread than domestic sewing. More heat is built up on the needle, more ins and outs of that needle in the fabric at faster speeds, it all causes abrasion on the thread itself. Don't cut corners on thread quality. JMHO Oh and batting too: higher quality batting will be better for your end result,and your thread will find it less abrasive too.
For using specialty threads like Rainbows and Metallics, here's my advice: I use them and love them. Superior is my brand of choice. When I use delicate thread on top I always ALWAYS use a thin smooth thread in the bobbin. Sometimes it's Bottom Line, sometimes So Fine. You have to use a thread that has NO fuzziness or slubs in the bobbin because metallics and trilobal polyesters like Rainbows do not like anything they can 'catch' on. Also scratchy batting is not a good idea for these threads. Also, you need to quilt a bit more slowly, lessen both the top tension and the bobbin tension, sometimes up the needle size, and/or loosen the quilt sandwich a bit too. Metallics are made by wrapping a poly core with the metallic on top and by it's nature it's a bit rough. It can be finniky on any longarm, but my A1 runs it fine when I do what I need to do to make it work. I do expect a bit more breakage with metallics though, so I try to do short quilting runs with it, then stop for a few seconds. This lets the needle cool off a bit. Heat buildup is your enemy. I love to use Rainbows and sometimes I get excited and get going fast, and wham, a break. Totally my fault. If you play by the rules with these threads, you should be able to use them.
Now, a plug for the A1. It is very easy to maintain and all electronics are 'plug and play' style, meaning all you do to change electronics or upgrade, is plug in an end on a wire that looks like a phone jack or usb jack or plug in a new chip if needed. Super easy. There are 7 oiling ports (access holes in the body of the machine) that you put oil in once every 8 hours of sewing. Four times a year, you grease two sets of gears that are behind round access doors. Easy peasy. Clean dust and lint off the bobbin area and needle area and tracks with a paintbrush.
The actual use of the machine is very easy. It can be fully controlled from either the front or back (front for freehand, back for pantos). There are less buttons and switches than on other brands, so very easy to learn. It is extremely smooth and seems to fly over the fabric. Some people will tell you it's bad to "quilt in the well". They are referring to the roller setup on the A1 which has the front rollers just at the level of your quilt. The Gammills have a different roller configuration where the front rollers are hidden underneath by your feet. This creates a 'waterfall' type of edge in front... you don't have 'reach' over the rollers to quilt. However, the A1 even with the roller there, is not hard to reach at all. I actually prefer to rest my arms on that roller. LOL I find the recessed roller style of the Gammill to be awkward to load with. So that really is personal preference, and in all reality, which ever style of rollers you have on your longarm, that's what you'll get used to!
The A1 allows you to sit to quilt without any retrofitting on the rollers... just pull up a stool and go! On the Gamills, the rollers can get in the way of your knees... A1 comes with the Ergo Lift, which I love. When I quilt from the front doing custom, I raise and lower the table to help with the ergonomics and my tired old body. Doing pantos, you want the table lower so the lift is great to have. It's on a remote control so it's easy to change whenever you need to.
The table on the A1 is build like a suspension bridge. Very sturdy and strong. No wobbles or sags.
I could go on and on about my A1. LOL
I see you live in OR. Did you get to MQX West a few weeks ago? I hope so, there were all the machine vendors there to try. I know quite a few A1 owners in that area, I am sure one would love to have you over to spend some quality time playing... Megan Best is the dealer for the PNW, she lives in Vancouver WA but could get you in touch with an A1 owner in your area.
Let me know if I can offer any more help. Good luck!!
. In a nutshell, I love my Sweet Sixteen. It's very basic, which means I won't outgrow it- nothing to update, just me 
