I've always used the dealer for tyres on the modern bikes (on the 1970's Honda's I fit my own). Only once have I deviated from this, and the bike came back with scuffed and chipped rims, as well as a vibration that wasn't cured by balancing (three separate dealers tried for me) and which eventually caused me to sell the bike, as it annoyed me so much. This was the third set of tyres that I had on the bike whilst I owned it, and it went in without exhibiting any problems and with perfect rims too!
Off to the dealer tomorrow for annual service/MOT, brake fluid and final drive oil changes with the K1300GT.
With the old bikes I am happy to do just about all of the work (except for electrics) including engine/transmission overhauls, however the newer ones with all of the electronics don't give me the same level of interest to work on (and I dread finding an electrical fault on reassembly that I've no hope of sorting out).