Hi have a Fenix 5 and very happy. I had an out of warranty issue with a 910 and Garmin were brilliant. There is a thread on here somewhere about it, but in summary, my 910XT stopped working 4 days before IM. I rang and asked if there was anything I could do (thinking of buying a refurbished unit) and in short they sent a brand new whole kit ( watch and HRM) to my motel at no charge. I couldn't be happier, hence the upgrade to F5.
I think how you deal with them has a lot to do with it (as with most companies)