I invested in a Studio, having had shoulder problems in the past. I use both Go and Studio dies and am a member of a Yahoo forum pinsandneedles1 where Kathy Tucker sells Go dies at a good discount. You can only buy Studio dies on the
http://www.accuquilt.com website. To use a Go die on the Studio, an adapter is necessary. I have invested a LOT in dies, but I use the Studio all the time and it has tremendously increased my accuracy and joy
in piecing. I even use it to make Leaders and Enders (Bonnie Hunter) so I always have one of those starty/stoppy fabrics that Alex is always using, when I'm piecing. That way, I'm working on two quilts at once. I have to admit, I have a big bunch of sewn together (2" squares and triangles) and have yet to make a quilt with them, but that's coming.
Either way, join the Yahoo groups accuquilters and/or accuquiltstudio for more information. Ebony Love has done wonderful Youtube videos on efficient use of dies and now has a book that is packed with information.
http://www.amazon.com/Little-Book-Fabric-Cutting-Tips/dp/1938889002/ref=sr_1_1?s=books&ie=UTF8&qid=1355605683&sr=1-1&keywords=ebony+love
There is also her
http://equivalentdienotation.com/ which is a way of figuring out which dies to use across cutting systems. Learning the language of the measurements took some doing for me, but I'm not a math whiz and really don't like formulas for half square and quarter square triangles.
You won't regret either system, but if you have the space and financial resources, I'd highly recommend the Studio.