Before I moved over to the dark side of AG I did quite a few kits.. I was v lucky and had no stuck ferments from 3 x Wherry kits and would recommend that as a lovely beer!
Also any Coopers kit I did turned out magic, depends what you like, but with summer coming up (hopefully) I can recommend the Coopers Mexica Cerveza, chilled right down and with a wedge of frozen lime in the glass! Or make the Aussie Lager (another good un) and enjoy it as we spank em in the Ashes in later summer (much larger fingers crossed!!)

Re the keg - I had a problem with my Beersphere not keeping pressure and I took it back to the LHBS and amazingly I was tightening it too much! I was leaning on the top too much trying to get a good seal, and it was bending the plastic thread at the top, making a gap.. the chap in there pointed this out as I showed him my technique (oeer madam!) - so check that out too... I never thought it could be that, but now i just do it really carefully and don't try and "crank" it on too muc.. Ever since he showed me how to do it, it has held Co2 really well!
BJ74