How do the Elac Uni-Fi UB5s compare to more expensive bookshelf speakers?

Heard ’em... my takeaway .... Meh?

IMO .....They are "okay" as either a "B" system speaker or a "C" system desktop rig, but again IMO, they are pretenders and certainly no contenders against , inter alia, KEF or DYNAUDIO as your primary speaker choice.

With a properly matched system, the latter strata speaker choice will smoke ’em.... not even close.

Here’s a review

http://noaudiophile.com/ELAC_UB5_Listening_Impressions/

I would not buy them unheard on a blind purchase primarily based on reviews

AND

Don’t get tempted into kidding yourself that their appeal -- almost totally based on a lower price point --- does not have significant warts or compromises in your peak performance expectations and/or a proper system synergy quest.

Choose wisely..

Thanks for your help.

heard both Unify and LS50 at hifi shows; LS50 are better to my ears, but ELAC'S q/p ratio is higher.
to say it all, I may go for a Debut B5 which is even cheaper than Unify and sounds better to my ears (and many comments agree 'round here in Italy). that was really impressive for the price.

...that is: if your budget is 1500$, then you may have better choices (e.g. LS50 and so on); if your budget is 750$ but you're thinking of stretching it ("OK, after all, what if I don't eat and feed my familty for a month or two ?" just kiddin' :-D ), then I sould seriously consider ELAC if you only buy new.
...or a pre-owned LS50 otherwise ;-)

but what I mean is that I think you may be happy anyway with those ELAC's, though there are better speakers out there.