Hey Chris, nice to see ur thinking about moving on to better things
As an Android enthusiast, I can assure you that you'll find the switch to be well worth it. With Google behind you, there is rly nothing you can't do with an Android phone. Google Maps alone makes it worth it, especially the FREE turn-by-turn navigation that rivals all paid GPS units.
The other feature that makes Android stand out is Voice-to-text. Any app that has an input text field will allow you to turn speech into text. I do it when im driving and texting someone, although at that point its not texting because Im not typing, but you know what I mean. And with Froyo (the next Android Update, aka 2.2), which the Droid X will be getting by summers end, you have the option to unfilter curse words!! It works really well lol.
Another unique feature of Android is the Voice Search. Its undoubtedly one of the coolest features of the OS and you will use it ALL the time when you learn its power. To be able to say "Restaurants" and have it bring up a list of places near your location, or to say "Navigate to (your destination)" is like watching magic being performed before your eyes!
And lets not forget MULTITASKING!!! This rly needs no explanation, all opened apps run simultaneously. Nothing gets shut off when u switch apps. Of course iOS 4 comes to mind, but dont get me started on that. Everything it does Android ALREADY does. Verizon rly did get it right to market their Droid lineup as "Droid does".
There are currently two things that make me upset about the Android OS.
1) No support for animated gifs, which means if you rely on weather radars n such then you are kinda sol. HOWEVER Froyo WILL support animated gifs, so you will have to wait till the end of the summer when it releases for Droid X.
2) Small contact picture when making a call. Google only supports 96x96 px contact pictures. So even if you assign a high quality picture to a contact, it will shrink to that size when synced to ur gmail account. When making a call, the quality of the picture is horrendous, not to mention you have this tiny picture. It rly is embarrassing and has not been fixed since Android released in 08. Hopefully with Gingerbread (the update after Froyo) releasing Q4 they will fix it. That update is going to include a UI overhaul.
If you ever decide to root your phones, which is the equivalent of jailbreaking on the Iphone, then you will be introduced to what is undoubtedly the most loyal and enthusiastic community of any mobile OS platform! There are so many goodies that come with a rooted phone, such as custom themes and custom roms which add even more functionality to the Android OS. My suggestion is that once you become familiar with Android and feel like taking it to the next level, root your device and explore the wonderful world of custom roms!
As far as phones go, I would get the Droid X. Sure the Incredible is a great phone, but the Droid X is miles ahead of it, as much as it hurts me to say (im an HTC fan). The less a company customizes the Android OS to their liking, the faster it gets updated when Google releases their updates. The Incredible has Sense UI which, although was the king of Android custom UIs, is being overshadowed by the number of third party widgets/home replacements that once made it stand out. And like I stated before, the Droid X will get Froyo by summers end, which brings so many new things to Android like true Adobe Flash support, animated gifs, business features, a huge performance boost, using the camera flash while recording videos, and just so much more. HTC stated that Sense 2.2 will be available sometime this year but who knows when that will be.
Now lets look at it from a Rooted perspective. When rooted, you can load custom roms which I stated before. This means that developers can and will port over custom UIs, like Sense, to be used on non Sense devices. So think Sense UI on the Droid X. However, this does not work well unless the hardware is nearly identical, and even then its not a perfect port. However, it is super easy for developers to make a stock rom, aka vanilla rom, that will completely replace a custom UI, bringing it back to the default way that Google made it. This means that if you get an HTC phone with Sense UI, u will have the luxury of being able to have both HTC's custom UI AND the default, switching between the two whenever you want.
Software aside, there are the hardware differences which obviously cannot be updated. So that already makes the decision easier for you if you are concerned more about hardware capabilities than software.
And lets talk about carriers. The one advantage you had with the Iphone was that it was on ATT which is a GSM carrier (sim card based). This makes it easy to swap phones and use ur same sim card, and gives you the option of buying a local sim card based plan when u travel overseas. In addition, Verizon, being CDMA, does not allow you to use voice/data at the same time, which ATT does, as im sure u've heard in their commercials. Its one of the things preventing me from going to Verizon (with the other being their rediculous prices). Sprint is also CDMA, but with 4g you can do both when you are in a 4g area. The one downfall right now is that you have to pay a $10 premium on top of everything else when you buy a 4g phone, regardless if you have 4g in ur area or not. The HTC EVO 4g is an amazing phone, and you can go to a number of sites to look at a EVO vs Droid X comparison. The other 4g phone going to Sprint is the Samsung Galaxy S Pro which has a keyboard. And Tmobile, the carrier im on, has the Nexus One (my current phone) and is getting the Samsung Vibrant (our version of the Galaxy S) in July. Tmobile will have the fastest data speeds by the years end in part to their HSPA+ rollout, which is currently being deployed at a rapid rate across the country. They have to call it 3.5g, but dont let that fool you, it is faster than Sprint's 4g. In any case, u have options no matter which carrier you switch to.
There are so many advantages that Android offers over the Iphone that this post can go on for a while. I'd recommend you read up on any of the Android forums : Here at Android Community, Android and Me, Android Police, etc. And be sure to read up on rooting as well. If you are gonna stick with Verizon then you cant get either phone atm, so might as well get ur Android knowledge up!!!