Overall, Deere has a larger dealer network.
Who has better service, without knowing both local dealers...no way to say. Even then - its unlikely the hand full of members have experience with one, much less both.
If one is AgPro - well, go with the New Holland. Actually AgPro is good here in Ohio with sales/pricing - just bought a ton of chains out - but the cuts to service are becoming clearer.
Deere/Kubota/Massey/New Holland - all have plenty of parts sellers online and info on products available via web.
Reality is most users visit service for one thing...to buy parts to DIY. With the web...that can be filled online.
Even if these are the only 2 "local" brands Messicks and Bruno's for example csn serve your Kubota and Massey needs very easily via the web for equipment too...and might be cheaper to boot.