ok, with the caveat that I am certainly not an expert, but I have done a lot of reading because I've had the same questions as you:
1) the effect of creatine seems to be to increase the energy available to the muscles
2) this will probably enable you to lift extra weight/do extra reps
3) if everything else is right (eating enough/sleeping/resting etc) this may mean you put on more muscle. However unless you are very advanced you will be able to build this muscle eventually anyway without creatine just by sticking to your programme.
When you stop taking creatine the extra energy effect will also stop so obviously your lifts/reps will be less. Yes, any muscle you put on whilst taking it will stay, but how much of that was actually down to the creatine? no way to tell.
As you said there is significant and immediate bloating of the muscles due to extra water. Do not underestimate the psychological effect this will have.
I would be wary of anyone saying "I took supplement xxxx and got massive gains" without hard scientific evidence. This sort of person is the reason that companies selling supplements are multimillion dollar businesses. Again do not underestimate the psychological effects on someone who's spent a lot of money on tubs of powder and wants to justify it.
This is not to say that creatine doesn't work because evidence suggests that it does have an effect. But how much of an effect will it have on you, and is it really worth it? I suppose you won't know unless you try.