Today I sent in my order for an Alexi-200 ESP LTD (and I'm so excited!!!! ) It has a lincesed Floyd Rose tremolo on it, but I've never owned a guitar with one of those on it. I've been watching tons of video's on youtube to help me learn how to set one up, but I know it'll take practice to really learn how to do.

My real problem is that in one of the vids, they mentioned that if you play a higher gauge string, you'll have to add a spring to equal out the tension. I play ernie ball power slinkies (.11 .14 .18 .28 .38 .48) so I can tune to Eb standard. I have no problem playing a low gauge if needed be, but if I wanted to play power slinkies on the Alexi-200, would I need to add a spring to equal out the tension?
no. not really. if you want to drop tune, you have to take the back cavity plate off, and adjust the screws to change the amount of tension on the strings to even them out.
Peavey XXX combo *upgraded screen resistors, Tung-Sol's, and 6L6's*
Schecter Syn Std. * modded, scalloped, and worn*
Schecter C-1 Elite *still sexy*
Ibanez AEL 12-string

"He who sticks his dick in peanut butter is fucking nuts"
I have FRs on both my main guitars, and I've never had to adjust anything but the height of the bridge. I simply tuned them to Eb, and adjusted the bridge until I got the action I wanted.. It's perfectly even, and the feel of each string is just right. I check the intonation each time I restring(about once per 1-2 months) and it's never off. At least not far enough for any of my tuners to pick up.

I used to have a licensed FR on my Jackson, but it wasn't really any different in terms of handling, tuning, intonation or staying in tune. Works perfectly for me, and it always did!

One thing, though. Stringing up can be a bit tricky the first few times, as it's not like a tune-o-matic bridge, or a standard stratocaster pivot bridge. You have to cut the strings, and lock them in place at the bridge, whilst the neck part of stringing is just like on any other guitar/bridge system. Due to the floating nature of the bridge, each string is part of evening out the tension between all the strings. For instance, tuning the E3(low E) string up will cause all the other strings to drop slightly. Take this into consideration when tuning. I don't know if you've seen this, but it certainly helped me when I got my first FR http://floydrose.com/originaltremolo.html

Personally, I wouldn't go with anything but a Floyd Rose. People complain that they don't hold their tuning during extensive tremolo arm usage, but that's not at all the case for my part.