Why does every body use these things,i am happy with my Boss GT-10 in front of the amp.Is my sound getting better with one of those ---lators?, and how?
Well, It all depends what sound, tone you ara after.
The beauty of the Dumble (good clone) is in it’s preamp section and D preamp is actually very high gain circuit! With external pedals you are adding unnecessary noise and you are changing the TONE. The best tube amps for the processors are stereo power amps like VHTs, Mesa etc. or non reverb, one channel tube amps with low gain inputs: Hiwatt, Bassman, old fender BASS guitar tube amps etc.
On the other hand you can try GT-10 in the FX loop in D style amp. Because GT 10 has input and output gain regulation and high impedance input it will work well. Also you can use it’s EQ section and noise reduction with loads of nice effects.
You can do all this with C-lator plus TC Gmajor which will also switch amp’s channels with MIDI or any other good reck unit.
My favourite guitarist Allan Holdsworth uses loads of processors together with two tube amps and sounds incredible (IMHO).
Anyway whatever makes you happy that’s the way to go.
Cheers