I'll start off by saying this: I like Infopath - well I want to like it.
It is VERY much a v1.0 program. Hopefully, Microsoft will continue to develop it further in the next few iterations.
Case in point, I was trying to autoincrement field in a repeating table. I did my usual things - googled, google groups, documentation - nothing found a solution. I tried quite a few things from Google groups, most didn't work at all and some would sort of work.
Anyway, after half a day of trial and error and reading the docs, it appears that I can use an expression field and have its default value set to position(). Thats great but it shouldn't take half a day to work out. I mean this is a fairly standard thing to want to do.
Hopefully in Office 12 Infopath will be improved. As I said before I think it has the potential to be huge - in our company for example, there are literally hundreds of documents someone has made as read-only Word templates available on the intranet, but these need to be printed out and filled in by hand. Obvious job for Infopath, however at current state it would be a big job to convert.
I might wait for the next version before I recommend that upgrade.....