Is the V3i a good fit for you? Or, are you a good fit for the V3i? With this particular unit I feel the latter question is the pertinent one.
I love my V3i for my purposes. It does many things very well v.s. one or two things extremely well. A very flexible platform, and that is the top feature, imo. The tones are vastly different from the AT series, so make sure you watch a video or two on tone ID.
I took my toys apart as a kid to see what made them work. At 8 I wanted to be a game programmer and was copying/modifying code on the daycare computers in early 80's. As an adult in my spare time I've learned to do my own computer repairs both hardware and software, and I learned to write html, css, php, java scripts, etc. so I could make my own websites. I like complicated graphic software like Photoshop, illustrator, etc. I've always loved a good brain puzzle. If you're a persistant, patient learner, you'll have no problems. If you are an obsessive challenge taker you'll do great. I feel these qualities are why I fit well with the V3i.
Everyone is different. I doubt any other machine will teach one as much about the nuts and bolts of detecting as the V3i will. I understand why one would not want to own a V3i, but I understand exactly why I will always keep mine.
