Scansonic MB-2.5B vs Sonus Faber Lumina III

These two will have completely different presentations, and your current electronics and listening preferences should be the biggest influences in the decision. 

The Scansonic MB-B series to me is an incredible speaker for the money. They have a signature similar to many Danish brands, like Raidho, Borresen, Audiovector, Dynaudio. It is very open, transparent, still musical. The ribbon is not as refined as the higher end brands but it is still very good. I’ve heard rooms that was very holographic with them. They project a more forward soundstage. 

The Sonus are very appealing / pleasing to listen to but at the expense of some resolution and speed on the frequency extremes. They project a more relaxed soundstage and feel a bit more romantic.

What electronics would you be driving the speakers with?

Agree that some of the newer SFs including the Lumina III are breaking the typical SF sonic signature, but they are still very forgiving speakers. Nothing wrong with that. I would say the Scansonics are much less forgiving, depends on what you will prefer. 

Primaluna is a great choice to upgrade to. They make one of the best and most versatile tube amps for their price range. 

@missioncoonery Which Primaluna did you have, and did you upgrade the tubes and fuses in them? In stock form, PL is not so great, but considering the OP's system, it's not a bad choice. Upgrading to top notch tubes and upgrading the fuses, as well as aftermarket power cable all take the PL to another level.

@jerryg123 Agree, but compared to the OP's Cambridge Azur 851A, it's a great step up.

@jerryg123 We will have to agree to disagree. I had the PL HP with KT150s and Brimar CV4003, SR blue fuses and aftermarket power cord. I owned the Scansonic MB-6B, and they powered an 18x23 room. It wasn’t endgame reference, but it was quite satisfactory given the level of investment. I know there are a few others in this thread that have also owned a PL HP and were very happy with them. I won’t name them but if they want to join in they can. 

The Scansonics the @jetter listed is being sold by Alfred Kainz if Highend Electronics. 

@musicaddict The Borresen Z3 Cryo I now own we’re sold to me by Tyler Mueller at Next Level as well. 

Both Alfred and Tyler are amongst my favorite dealers in the industry. Just wonderful people who provide incredible service.