I was on call when I received my order so waited to do the first upgrade (I bought two iPhone batteries). Both phones have been upgraded and are working perfectly. Oddly I bought both phones at the same time but found they were both slightly different, I guess this speaks more to the Quality controls placed on the items being produced for apple. On the first one I found that the 1.5mm screw for the front panel assembly cable bracket had a retaining ring which prevented that screw from coming out of the bracket (on accident (and just luck) ) that was the last screw I removed so it worked out well the whole bracket and screw came out together. (kind of making things easier). On the second phone the same screw was this time replaced by one of the 1.2mm screws and had no retainer on it making it a bit harder to reinsert but everything did go back together just fine. The only other problem I experienced (and I had it with both phones) I must have been tipping the screen to far when putting the front panel assembly cable bracket back in place, in boht cases I heard the distinct snap of the cables being reinstalled so was certain they were good to go, but once I put everything back together I had to take them back apart and could hear the distinct snap of one of the cables being pushed back into place again the second time, but then everything worked flawlessly after that. Thanks so much for the great instructions they were quite easy to follow and each phone was back in operation about 45 minutes from start to finish (even with having to take them apart twice). Not that I hope to have to work on these phones again but I look forward to "fix'n it" myself if I do.
The magnetic mat saved me from having to crawl around on the floor looking for a dropped screw (and trust me these are small screws I might have lost them if it weren't for the mat) on a couple of occasions. The iSlack tool was also I'm sure a time saver it didn't feel like it because I didn't have to struggle a bit to get the front panel apart without it I think I would have been more timmid about pulling on the screen in fear of ripping cables loose. The iSlack was a breeze.
A note to the ifixit team, thanks for including replacement pentelope screws with the phillips head a pleasent and thoughtful surprise.