Me too! CM7 is great!
I started with rooting my phone of course. Gingerbreak v1.2 worked perfectly. Easy as tapping a button on the phone.
Unfortunately ROM Manager didn't work for me. I heard he included a new version of the recovery program with the app. It didn't work on my phone, even when after multiple re-flashes. When I tried to flash the ROM, it wouldn't load recovery, but ROM Manager still did a complete wipe of my phone so I ended up right back on day one, but still on 2.2.2. Man I was upset, cause I'd lost everything on my phone, except for my music and images on the SD card thankfully, but didn't get anything out of it.
Went back and followed the instructions on XDA forums which involved flashing a recovery program they recommended on the phone, and downloading a remote terminal app on the phone. Did that, loaded CM7 on the SD card, went into recovery, cleared all necessary data, flashed the ROM, reboot and done!
It's GREAT and changed everything about the phone, right down to the animation when the screen turns off. It's pretty awesome by itself and comes with ADW Launcher integrated into the ROM. Honestly, the ROM is great out of the box and doesn't really need many changes.
Only three negatives I've found.
One is that the ROM comes with literally almost no applications installed. This is great for streamlining the phone but it's missing the essentials like Market. The thread over on XDA about this rom has a link right in the first post where you can flash the bare essential google apps like Market, so it's not really that big of a deal. Just takes an extra step. Seems to me that they should have just put it in there to begin with, but hey, they did an awesome job with this ROM and ask for nothing in return so I won't complain.
Two is that like all the other standard software T-Mobile supplied with this phone, Swype disappeared. I love Swype! And you can't download it from the Market. I tried a few other similar 'boards but they either had ads to entice you to get the paid version or they didn't work that well. Disappointment. THEN I found Swype Beta. You have to register, but you can download the app and install it on your phone. It's even better than the original Swype! It has a new voice to text generator made by Dragon something or other, I think. It works unbelievably well. Fast and accurate to an incredible degree. Want to know how accurate? I dictated this entire post to my phone. I'll have to go back and correct a few capitalization and paragraph spacing issues but it's picking up everything word for word.
Three is that Wifi calling disappeared. Some don't find it to be too useful, but it always worked for me. I miss it, because in my living room where I spend the majority of my time at home I have a cell signal black hole for some reason. Wifi calling let me kept sending messages and calls out when I needed to without walking around the room hunting for a signal. What's interesting is that for some reason since the ROM flash I actually get between half and full bars most of the time. Cool.
Only major change I've made other than my app compliment is to change the standard ADW Launcher to ADW Launcher EX since I'd already previously paid for it. I found it to be a little faster than the free version and the one packed with CM7.
Love my phone. It's now running 2.3.7 which is better than some of my friends new phones.
I'll manually add a screenshot in this post, I don't think the voice to text thing will figure that out lol.