Quicksilver M60 tube instead of Bryston 3b-st

Currently there is a possibility that if I will sell my Bryston 3b-st I can get used Quicksilver M60 instead for almost the same amount since I want to switch to tubes on the front-end.

Will that be an upgrade sonically? What will I benefit and what will I loose? Am I suppose to aquire higher power amplifier such as VTL MB125 or Rogue M120(used) which are at least $1k above from what I can get..? So I have 2 choises: either wait until I'll have a budget for Rogue M120(used) or just simply buy Quickies. I currently have EAD DSP7000 MK2 unbalanced version on the digital end, Benz Micro M.9 -> AR PH3 on the analogue end. I do use right now passive settings for the preamp but I can use active settings as well with upto 12dB of extra gain which I've only needed to reproduce large orchestras. I've made this preamp from DACT parts.
Partially will depend on the speakers you will be using. Quicksilvers have few peers in the midrange. Period. They can sound a little fat in the bottom and rolled on top, but that will depend on speakers and cables used with them. They will probably not work well with the cables you used with the Bryston and vice versa. However, if you properly set up the Quicksilvers, they will likely sound significantly better than the Bryston.
This is the type of question which no one else can answer for "you". It all depends upon what you value in the way of sound. I've owned both and they are both good amps. I personally think the quicksilvers are "better"--but there are many who would say the opposite. If you check audiogon regularly, you will see that the various quicksilver amps are almost always available used, and that you can always sell your Bryston for a good price--so don't feel pressured or in a hurry. Good luck, and have fun.