They're a bit fiddly to set up, especially if you're changing string gauges, you have to adjust the spring tension as with any other trem, but the method is different. They do work fine with 10's though.
Setting the intonation is a bit of a pain too, but certainly no worse than a Floyd and probably easier on the Flyer than on the more upmarket models (if I remember right!)
Get strings with reinforced ball ends (like Ernie Ball RPS, if they still make them). Kahlers tend to break normal strings pretty quickly, unless modern strings are sturdier than they were 25 years ago!