I work for a Two Way Land Mobile radio company. We sell Kenwood, Icom, Vertex and M/A-Com (now Harris) equipment. We have tons of Kenwood TKR-750's, TKR-751's, TKR-720's, TKR-850's, TKR-820's, TKR-830's, NXR-700's, NXR-800's and NXR-810's... We have sold a few ICOM repeaters with mixed results. We have also sold tons of the M/A-com Mastr III's.
The Kenwood repeaters are hard to beat. They have mechanically tuned preselectors and are very reliable. If you get a TKR-750/751 (VHF) or a TKR-850/851 (UHF) you should have years of great sounding repeater service. They are about as plug-n-play as it comes. They have excellent built in controllers that will do most any function one would need. Sorry no digital voice ID'er or time announcements, etc...
If I was going to go the easy route to get something on the air quick witout hesitation, I would go with a Kenwood...
Having said that, I have "built" or "assembled", retuned, rebanded and repaired several GE Mastr II repeaters. They are hard to beat. If you can get one, and that shouldn't be to hard, there are 1000's of them out there, you will have a well engineered and reliable machine. So far I have built 3 from peices on 2m and 6m and rebuild countless others on 2m and 6m. I haven't worked on any for 70cm yet, my company used to have a dozen in LTR UHF service and I did rebuild a few PA's.
I have enough parts to built a half dozen more right...
If you have the time, go GE Mastr II. If you don't, go with a Kenwood. You won't be sorry.
just my $0.02 worth.