I've installed both types, started them with starter punches and switched to regular punches with the dimple. Coiled springs go in far easier, no contest.
I bought some coiled roll pins on Ebay recently to replace one that mushroomed on me. Price seemed reasonable and the guy has different sizes - including the trigger guard pin and the bolt catch pin. I paid about $4.50 shipped for 12 of one size. I have to say, these pins worked really well - with the tapered ends, they went in very smooth.
Look at his store - I think he sells larger numbers in bulk as well.
Here is a link to what I bought:
http://www.ebay.com/itm/151628889992?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/6-Trigger-G...944186?hash=item25a58802ba:g:W6AAAOSwymxVQvI8