I have personal experience with only two: a Cricut Expression and a Silhouette Cameo. The Expression can only cut from proprietary media cartridges and cannot do any ink work. The Cameo can cut anything vector-based, including any non-bitmap font, and also hold ink pens or colored pencils instead of a blade. As you'll see in an upcoming video I'm finishing up, the Cameo can do optional Edge IDs, fold line highlighting, fold line scoring, and of course cut line cutting. I've read about people using some RoboCraft thing, but haven't personally used it.
The Cameo can cut parts any size that will fit on a sheet of paper, and supports paper size up to 12" x 24". As for small parts, I've used the machine to cut out parts only a few millimeters in size for my kid's costume. Although the machine is capable of cutting tiny parts like that, I'm not far enough along yet to have comparison data against hand-cutting such small parts. I may end up cutting the minuscule parts by hand and have the machine do the other parts, but I don't know yet. Other people may recommend other machines, but I like the Silhouette Cameo.
Check out the second photo in post #201 of this thread to see a part cut on the Cameo so small I'm holding it with tweezers.
The Cameo can cut parts any size that will fit on a sheet of paper, and supports paper size up to 12" x 24". As for small parts, I've used the machine to cut out parts only a few millimeters in size for my kid's costume. Although the machine is capable of cutting tiny parts like that, I'm not far enough along yet to have comparison data against hand-cutting such small parts. I may end up cutting the minuscule parts by hand and have the machine do the other parts, but I don't know yet. Other people may recommend other machines, but I like the Silhouette Cameo.
Check out the second photo in post #201 of this thread to see a part cut on the Cameo so small I'm holding it with tweezers.