There is one really good benefit to Apple. They don't make a ton of models, so everything works on it, which is in the iTunes Store.
For me tho... I have custom skins, over $1200 in value from grabbing the free apps daily off of Amazon, I can install hacked versions of games, and I use mine to tether my computer on occasion. What I would lose, switching to Apple, isn't worth it for me. I think the best thing about the Amazon store is the free alternatives to everything. With Apple very few apps are free.
If you're happy with Apple, then love it in your special way.
You should check out this site for some free apps...