I am actually turning some cases this evening with a Sinclair NT-2000 tool ( the new model is NT-3000) and it is in my opinion the best money can buy. It's very simple, and very accurate. It can also be run with a power drill which dramaticly speeds up the process.
Neck turning, like anything, can be taken too far. If you don't have a tight neck chamber, you might want to take just the high side off your brass. But that is all. We're talking about just taking off .0005". If you get carried away it can actually make matters worse.
If your chamber is tight neck, then I would take the brass down to have .001-.002 clearance on each side. My 6.5-.284 has a .296" neck and I like my loaded ammo to measure .294".
Hope this helps!