Hi Pierangelo. The direct answer to your question is ABSOLUTELY YES! The Hasselblad V system has delevoped an enduring superlative reputation over many decades for very good reasons. The V system is where two great design, engineering and manufacturing brains and companies got together - Zeiss and Hasselblad.
Ditto everything Flo said (I very much like his s&le shot too). Keep analogies out of it.
But, do remember that no camera or system "maketh the great photographer". Only you can compose wonderful images, create superb exposures etc etc. The camera and system just supports that.
Like you, but many years ago, I had a Bronica SQA system with 3 or 4 of their lovely lenses. This is a good kit for any user unless the Bronica system excludes components you need for your type of shooting (in the same way Hasselblad does not cover every user's needs) - the same applies to all MF systems. But the Bronica system is no more, so now may be the best time to exit.
There is little debate that in MF the Zeiss/Hasselblad lenses are generally benchmarks. But that does not mean others are weak - far from it. For ex&le, Mamiya makes some wonderful lenses.
I took on Hasselblad as a step up into superlative optics and a system that better fit my needs. I was only able to afford that because of the digi growth (and no digi comes anywhere near a full MF film image).
I have a 501CM, some backs, 45 viewfinder, 50, 80, 180, 250mm lenses. Every time I pick up the gear to take shots I am inspired. My next wish list item is like Larry suggests, the 120 Makro to fill a gap between 80 and 180.
Of course, trade your Bronica system for Hassey since you are obviously happy with 6x6; however, think twice before you let go of the Rollei 3.5T. A TLR is a wonderful MF to own and these are the best. It complements an MF SLR system.
I got a 3.5F (circa 1956) and I adore it (super silent etc etc) - different horse for different courses.
If you are committed to serious MF, enjoy 6x6, see value in superlative optics, and feel the Hassey V system covers all your shooting needs, then go for it. I'm delighted I did. Buying is good now but prices have been friming up since I did about 3 years ago.
However, if you're not that intensive a user; agree Bronica glass does the job (and it too is of excellent quality); the system suits your needs, why bother since you have a very good system.
Finally, a tip - be sure to have a good hand held light meter (incident and spot). I use a Sekonic L558 and it is superb.
Attached is a shot I recently took with the 180mm Sonar f5.6 CF lens. Of course it is nearly impossible to judge detailed quality over the net, but I hope you get the idea. My 25"x25" print is wonderful.
