What ones do you have? Some are easier to use than others. Maybe if you just stick with simple ones like pockets/AIOs etc? What is it about them that seems faffy? If it's having to use a wrap/cover - as above, try just pockets/AIOs? These arent always as reliable but some people get on great with them. Or if it's poppers - stick to aplix? Loads of people love Teenyfits and Easyfits, they are great and probably the closest to a disposable (also try Bumgenius etc).
As for the bulkiness - you are never going to find a cloth nappy as slim as a disposable but some come close (again, I recommend Easyfits - also Itti Bitti D'lish are brilliant and SO slim fitting under clothes). To be honest though most people grow to love the 'big bum' look - I did
I would say dont give up yet - give them another go. If you really hate them though then dont use them just because you feel you should. You should be able to sell them on the classifieds on here, if you say they are almost new then you should get a good price for them.