Re: hughes and kettner tube safety control
Owner of a Grandmeister 40 Deluxe for about a year now, and so far absolutely no issues concerning the tubes.
H&K make solid pieces of kit, and with so many sound and features, it's hard not to find an amp that wouldn't meet your requirements.
It's indeed a very "hifi", polished sound, so I would advise you test one before you buy.
For me, coming from other tube amp brands, I have found my home.