one thing nobody mentions (and i can't see why, it's IMPORTANT!!!). pee valves and front entry. unless you have the comfort of a RV at your disposal and the entry is right next to the parking lot these are important. It is like night and day, you can partially undress without any assistance and don't have to undress as often. Also, pay attention to the undergarments, they make a big difference as well. choose one that suits you well and is of proper warmth for the weather, you don't want to be sweat soaked by the time you are in the water but you don't want to be cold once in either.
Personally i prefer shells but neoprene suits are good as well (some people prefer them).
As said before the main issue with drysuits is the additional weight (which if you dress properly should be about the same as with a wetsuit that is good for you in the specific temperature you are diving), streamlining (you don't want to inflate the suit to the point of it bulging but you don't want to squeeze the undergarments either) and trim (place your weights in proper position for you). As long as you have these covered you should have no issues, the invertion becomes a problem mainly when you overinflate the suit but the problem is of magnitude, especially if you are not nimble / flexible / powerful enough. basically consists of you floating legs up while being too buoyant, in this situation you can not vent air (the valve is on the shoulder) and you are floating up (which makes it worse progressively). In a nutshell the solution is a forced roll using the fins as means of generating momentum, you roll and bring yourself in legs somewhat down position, this allows for venting of the drysuit. during the maneuver most people loose depth and some loose orientation (remember compass bearing and look at the bubbles). It is not a big issues if you keep the initial dives short and shallow enough to allow for somewhat fast ascents in case you miss the maneuver. Other than that the only difference is that you need an extra LP hose and you are connected via it to your BC / tank / regulator, you have to unhook the hose to dump it (not a good idea any way while in water). i noticed a 5-10 % in air consumption once i started diving dry. i'm 6'2" and about 205, if you are about my size and want to try my shell suit just let me know.
Personally i prefer shells but neoprene suits are good as well (some people prefer them).
As said before the main issue with drysuits is the additional weight (which if you dress properly should be about the same as with a wetsuit that is good for you in the specific temperature you are diving), streamlining (you don't want to inflate the suit to the point of it bulging but you don't want to squeeze the undergarments either) and trim (place your weights in proper position for you). As long as you have these covered you should have no issues, the invertion becomes a problem mainly when you overinflate the suit but the problem is of magnitude, especially if you are not nimble / flexible / powerful enough. basically consists of you floating legs up while being too buoyant, in this situation you can not vent air (the valve is on the shoulder) and you are floating up (which makes it worse progressively). In a nutshell the solution is a forced roll using the fins as means of generating momentum, you roll and bring yourself in legs somewhat down position, this allows for venting of the drysuit. during the maneuver most people loose depth and some loose orientation (remember compass bearing and look at the bubbles). It is not a big issues if you keep the initial dives short and shallow enough to allow for somewhat fast ascents in case you miss the maneuver. Other than that the only difference is that you need an extra LP hose and you are connected via it to your BC / tank / regulator, you have to unhook the hose to dump it (not a good idea any way while in water). i noticed a 5-10 % in air consumption once i started diving dry. i'm 6'2" and about 205, if you are about my size and want to try my shell suit just let me know.
gatcha 
