I was blessed to received the AccuQuilt Go (regular size) for a birthday/Christmas gift from my Dad & stepmom this past year. I haven't used it tons, but have played with it and so far love it.
Like you, I thought it silly to use dies to cut straight lines BUT having tried out the HST die, I love it. It cuts them already dogeared so that you can actually line up your triangles and they are already right. For me, that is a huge help, because I am terrible terrible terrible at getting my triangles aligned properly for sewing. And doing the "put 2 squares together, sew 2 lines 1/4" away from the line down the middle" method, I often still wasn't 100% accurate, because the pencil width of the line down the middle, the edge away from the ruler, etc.... -- my squares made from HSTs done that way almost never ended up exactly the same size as each other.
I think using the die, then, for the HSTs, will be loads better (it seems a lot more accurate, with the trials I've done so far). As I've a quilt coming up that is nothing but HSTs, I'm looking forward to trying it out! What I've been told is layer my fabric in the same way I would pair them up to sew, so that when they come off the cutter, they are already paired and ready to sew just like that (rather than cut all one color first, etc...).
I do wish the dies weren't so expensive, but I'm happy with it for now.