ARC REF 3 or MBL 5011 - what is better buy?

I think I need to add more info to my issue/situation. Currently I have Antique Sound Lab Flora (6sn7 tube based) pre-amp. It is a good pre-amp for the money. When playing CDs with small group of instruments (jazz) it produces great soundstage, good imaging, natural timbers. But when playing CD with the large orchestra music, the soundstage remains good , but I strongly feel that all presentation is loosing crispiness, transparency, even so the soundstage remain large. The impression is that somebody put curtains on my speakers. I think this is attributes to the ASL Flora in my system, so that is why I am looking to change/upgrade the pre-amp and ARC REF3 or MBL 5011 are the good candidates. Again, because the possibility of demo is non-existent, I would like to get as much opinions/suggestions as possible.

You do not specify but if you have not upgrded to Mundorf caps and NOS tun=bes in your Flora then you have not heard it at it's best.
It still may not get the job done for you but then again it may...If you have already done these things....never mind my post :-)

Unless I missed it, it seems that nobody even considered that the MBL is solid state while the REF 3 is a tubed preamp. I personally love the sound of tube preamps, but eventually you will have to replace the tubes which can hit the $1,000 range for excellent quality tubes. Vacuum tube equipment is a whole other universe which eventually will lead you down the road of tube rolling, etc. etc. You need to consider whether you want to walk down that road.

I bought my replacement set of ARC original factory supplied tubes for my Ref.3, tested and matched, for $330 nett.

Have to agree with Tvad, having lived with the Ref.3 for 3yrs previously, they are good partnered with SS amp--but not the greatest. Though given the choice (having briefly encountered a 6010D in a friend's system), I'd still opt for the Ref.3. IMO, they are still one of the best value pre-amp available today (considering price to sound performance ratio). Especially buying used, I believe that you'll preserve most of your dollars invested upon reselling.

If you love the sound of Plinius why not also try out their pre to maximize design synergy?