Unpowered, it has high encumbrance (3, I think, for light, and 5 for basic) and its warmth value can make it too hot in summer.
Powered, the encombrance drops (to 1 for basic power armour, and I think the same for light armour but I haven’t found one of those), and they regulate their internal climate to keep you Comfortable.
Also, how do I raise the chance of installing bionics successfully, and is there a limit on how many I can install? For some weird reason I found a huge stockpile of them in a sewage plant.
The formula for installation chances is fairly complex, and I believe it’s been updated recently, but basically you want to improve Electronics primarily and also First Aid and Mechanics. Your level of Intelligence is also a factor.
You can install as many different bionics as you like, but the only one you can install multiple duplicates of is Power Storage. Also, if you have a lot of active bionics installed, the user interface can run out of letters to activate them. If that happens, you may need to edit your save file to manually reassign them.