Battery strength was poor after 3 years--needed a new battery.
Repair went well, but it seems a couple of little things always go wrong that cause the repair time to balloon--particularly during reassembly. I dropped one of the 1.7mm screws into the phone and spent 15-20 minutes looking around for it under a magnifying glass. Then I didn't fold the battery adhesive tab back under the battery and had to take the phone apart again to carefully fold it correctly with tweasers.
Using a loose zip tie along with the included suction cup is a really safe way to pull the phone open without pulling it too far open.
Before getting all set up for your repair, double check that the included pentalobe screw-driver fits. The one that came with my kit at first was one gauge too large. iFixit service was excellent and sent me a replacement right away.