Theres ways around that. If you just switch the string to drop d, its gonna throw everything out of whack. What you can do is block the tremolo (there are devices to do this, or just use a fitted piece of wood) when you want to switch, and youll be fine. If i want to go more fully to drop D, setting back up takes maybe a minute or two for such a small change. Just have to rebalance things a bit, youre already most of the way there.
They can be tricky, but my first electric had a floyd, and a crappy one at that, and I was just fine.
Basically as you loosen the tension on the front (tuning down that string) the tension will go out of balance as if you were pulling up on the bar, so you have to loosen the springs a bit in the back. Reverse than when tuning back to standard. It takes a few minutes, maybe a bit longer at first, but its not a big deal. It is a bit more than just messing with the tuner like on a stoptail guitar. so if 10 seconds to 2 minutes is too big of a time jump then dont get one. If youre ok with taking a minute when you wanna switch, then go for it.