Hi, you will get differing opinions on this subject. Some people have had nothing but problems with the plastic pressure barrels, others no problems at all. I have 3 King Kegs with bottom taps and have had no problems at all. You just need to apply Vaseline to the tap and lid threads before tightening them, and don't over tighten them either. I think this might be the problem to a lot of peoples leaking kegs. If its over tightened I think it distorts the rubber seal? I have also fitted a pressure gauge to the lid of all of mine to help monitor what's going on inside. This is really useful so I know when the pressure is dropping as I'm drinking it and can recharge with CO2 before it glugs air.
Jas