Pulse, feednecks and Ions
Regarding Pulse and feednecks. I found my pulse too big to go in my Ion quicklock feed neck and spent some time sanding it down. Got it in eventually, so don't let any reported problems with pulse and SLG's put you off. It's easily fixable.
As for maintenance of an Ion, if you get the old/original model you do have to take the thing to bits to lube the bolt, and yes if you are heavy handed you can break bits off. Best thing is just be careful.
However someone I know has the new Ion and it is a bolt out of back method so no more taking the thing to bits to lube up.
I love Ion's to bits, but I would suggest an SLG, as I consider the Proto build quality better than SP.