Just finished up the 70 to 80 grind. Missed server first by about 20 mins (HATE my ISP who had me down for about an hour earlier in the evening) In any case....at 71 went SL/FG and had a blast. Made a slight variant putting 5 to bane later so my instance dps didn't suck. Also by high 70's even w' BT/Sunwell gear mobs are taking longer to die so a quick immolate speeds things along. Group quests, solo'ing, etc was fine. Only replaced one or two minor gear pieces but still have all the same bits. This setup plays almost exactly like an arena SL/SL but you have a felguard and a bit more nuke options. Only times I died is when I did something truly foolish and recovered from so many "oops" it wasn't funny.
A bit brainless to play but for endless hours of tab dotting, very gear forgiving, and live through anything I couldn't complain.
If you are not using it blow the 50g and give it a shot. Levels fast...like don't bother training and keep questing/grinding fast. Would I take it to naxx? No - but it will get you to 80 so you can pick a spec you like and get ready faster... Could also PVP decently.