Tara- I found that I had to use a shim (like 3 pieces of thin chipboard!) ALL THE TIME with sizzlits even with the adapter. I got the sidekick and it's GREAT- no shim needed. I would just get a big kick with a coupon and then you don't need the shims or anything else! It comes with a multipurpose platform that works as an adapter to EVERYTHING out there! I use my "old red" for mashing bottlecaps and cutting stuff that's too thick to put in the bigkick. You might want to wait on getting the big kick because sizzix is putting out a 12x12 cutter like the big kick sometime soon- it's on their blog.
Now that I've TOTALLY enabled you!