High Altitude

I just bought a gen4 34 that I am going to use in IDPA/SSP. I have been using my 19, but since I carry my 19 I haven't touched the trigger other than polishing it up some. Question Are drop in trigger kits from Vanek or glocktriggers, that are production/ssp legal, any different than polishing up your own parts, changing the springs and putting in an overtravel stop? Are they doing anything to actually modify the parts to change the geometry or is it just a highly polished setup with the same parts you can get?

Hi everyone, I am seriously thinking about purchasing a 550b for my first press. From looking at the posts on the forum it appears that the priming system on the 550b is the weak link. I know all presses need to be maintained, but how severe (or not) is this issue with the 550b? How often do you need to clean/tune/adjust the primer system to make sure it keeps working properly? and how hard is it to do?