Good call on Android. It's the way to go right now unless you like iTunes and/or already have other Apple devices. I got a Samsung Epic about 2 months ago and absolutely love it. It's fast, slick, intuitive, and powerful. And no, the Samsung Galaxy UI is not bad at all, in fact comparing to the DroidX a friend of mine has, it's a good deal better in many respects. But personally I'd prefer no custom UIs at all, or that the custom UIs be simply addons, apps, and widgets that you can add/remove at will. This is fully do-able, but the hardware manufacturers don't realy want it that way.
My one big complaint about my phone, aside from it shipping with Android 2.1 instead of 2.2 (come on!), is battery life. I know this is an issue on most Android phones unfortunately, but apparently the Epic is slightly below average for battery life (though at the time I bought it some reviews were saying it was better than the EVO, which benchmarks I've now seen have shown is not the case). That being said it does come with some benefits in exchange for lower battery life: full multitasking (more on this later) and an incredibly awesome screen (better than the HTC, and, for my taste, better than iPhone 4 due to brightness and color quality).
Unfortunately, if you don't have Swype, then you're really not able to appreciate the full awesome quotient of the Android experience. Swype is probably 25% of the advantage I see for Android over iOS, and hilariously it's in large part this way because Apple won't allow apps like Swype (as I understand it). Sort of cutting off the nose to spite the face kind of thing. Swype is *awesome*; anyone I show it to is blown away by how well it works. It's almost like reading your mind sometimes. And even though I have a slide-out keyboard, I find myself using Swype a lot more. The physical keyboard is still highly useful for anything with lots of numbers and symbols though.
Funny actually, I've not used an iPhone that much, and then only the 3GS, not v4 yet, but I really don't find it to be that wonderfully intuitive or well designed (UI-wise). But clearly I'm in the minority - although my iPhone-owning friend agrees with me, hmm. As I've gotten used to my phone I've come to appreciate many features and ways of doing things. Then I ask my iPhone friend about how he does x or y and he usually just goes "um... I'm not sure if you can", or "yeah, that's a lot easier than iPhone". To be fair, he's not a particularly technical user, but then iPhone should be easy to use for everyone, right?
As for other benefits over iPhone, well as I said above multitasking is a huge and obvious one. This is one of those things that really shows the blindness of Apple fanboys and how brainwashed they are by their corporate overlord (ok, inflammatory language, I know, but I'm sure you won't mine Renegade
). Before multitasking was available for iOS, and before it was known/rumored that it would be in iOS4, many, many Apple fanboys claimed it simply wasn't necessary, in fact was stupid, would just drain battery (yes, it does, but you can control that), and nobody should/would want it. Then iOS4 comes out with limited multitasking and woah, suddenly multitasking is awesome, but *only* the way Apple is doing it because their way is "the Apple way".
Here's the thing about multitasking: it's one of the most useful functions of my phone, and I can't imagine how anyone could delude themselves into thinking otherwise. This is what happened within 24 hours of getting my phone (true story): I had gotten the Pandora app to listen to music (great app, with a nice widget!), and of course loved using Google Navigation already, and naturally browsing the web was a big part of my phone use. So I was driving in the car, listening to Pandora, and had navigation live, so when new directions came up, it would mute my music, tell me what to do, and then go back to music. Beautiful! Already multitasking is proving useful. But then my girlfriend wanted to look something up while driving - a restaurant I think, in the city we were headed towards. Did she need to quit Google Nav or Pandora? Heck no, she just did it, no problem. No issues with data connection contention, no problems. But then the Yelp site was too cluttered for a mobile screen and it suggested getting the Yelp app, so now we go to install that, it opens Android store, still with the browser open in the background, downloads and installs the app, and now she's using the Yelp app, with the browser open in the background, and Google Nav, and Pandora playing music the whole time. No skips, stutters, or slowdowns during any of this. A few weeks later once I'd rooted my phone I installed a wifi tethering app and there was even more to do simultaneously - wifi tether, google nav (yes, we had mobile wifi going in our car while driving, one word: AWESOME), Pandora, browser. Multitasking is amazing and the OS handles it very well.
By the way I'm pretty sure there is a "metal detector" app on iOS as well, and it "works" in so far as you can use it e.g. for a stud finder (metal studs, screws/nails). I think it uses the magnetometer (compass hardware), probably same on Android. Otherwise you're right on though.