Welcome to the 150 club, we got ours installed just about 2 months ago. 1st in Western Canada, which is a blessing and a curse. Blessing cause we have an advantage over alot of companies which still run iGen3's, I think we were the only shop here to have a iGen4, and a curse because it's a learning process for everyone.
We've had some semi major issues already, most have been dealt with, Poly printing is still a big one though.
The most notable was 14x26 Cover having marks from a plate under the fuser, where the timing caused it to slightly buckle and hit these teeth leaving small imprints. The tech altered the timing, and have not seen the issue since.
The next issue was the TAB blade basically assembly, where the arm that opens and closes, should be able to do it smoothly, but was seized pretty good and would snap open and closed, causing the timing to be all out of wack and having the blade scrape off the patches in between the actual prints, causing the final print to look filthy.
Otherwise it's been great, color is great, quality is great, and it seems way faster than my 4 was.
There still is a few other minor issues with edge deletion (which cannot be fixed with image shift or border cropping), still trying to figure this one out.
As well I have skewing issues on some text weight stocks on bigger sizes.
All and all though, I like it.