i just found this thread and have a bit of insight for those interested.
first, Golfshot GPS is the best i can find for GPS. $30 is well worth it and it works fantastically.
second, for a good Instructional app, i'd have to go with Golfplan. it's from the same company that does Golfshot so i guess that's a good thing. it's with Paul Azinger and it's really cool. provides video drills that make it easy to swing properly. and good short game and putting drills too. i really like it. and it links up with your Golfshot account, which is sweet.
for swing analyzers, i prefer iSwing. it has great UI and Adam Scott is their featured Pro model and he's got a nearly perfect golf swing - a good one to emulate. V1 has a bigger library of Pro models but they're not as good quality. iSwing allows you to compare swings but not merge them. V1 allows you to merge. i'd still take iSwing though.
