Beeing a 750 S Formula owner myself now for roughly 10 years, i follow that debate with very mixed emotions... The bike is a joy to ride when fixed, many owners have done quite some millage on their fixed bikes. However, if you don't fix them, the engine can blow up to a an unfixable point. Fixing the issues will cost roughly 3.000 - 4.000?. Assuming you bought the bike at a market price level of 4.000 ? +/-1.000, this means a complete cost of 8.000? roughly for a fixed bike that can still keep up with modern, similar bikes regarding suspension, power (speaking of the 2000 spec formula...), handling, brakes etc. - and that said, it is truly a 80's design. Thinking of that, it is amazing (for me at least) that this bike still looks modern, rides like (or better) than many modern bikes and with the right exhaust, it even sounds great...
So - get the issues fixed (if not already done) by someone who KNOWS what to do and enjoy. If you fit on the bike (f.e. if you are between 170 and 185cm), it fits like a glove.
Is it trouble free like a BMW is at least regarded to be? No. But you can get it to a very reliable level with some modifications.
I agree entirely with SteveB's comments. Today, most of the Breganze twins and triples are fixed or about to be fixed. If I see how many engines Red passed through his workshop the past 5 years (and not all of them just for power increase but also for a lot of fixing) or Keith or OCT or others, the Breganzes do have their issues obviously, too. BTW: Steve forgot to name the broken or bent Rods on 120? engines. How many crankcases have a big breather in the front area now...?
But is it really a trouble free bike that we are aiming for? If so, this would be a) a very silent forum and b) it would be for a different brand like Honda, Suzuki, Yamaha or Kawasaki. Oh - no... they do have their issues obviously, too... :-*
@pf1: I have the very first bike magazine review's of the Breganze bikes. Quality was a big issue in all reports... broken airboxes, underperforming drum brakes, to small fork on the first bikes etc. etc. etc. ...