Not to diminish the PSB's. I am sure they are a good speaker and have read good things about. But since I never heard them and am a former Wharfedale owner, I must cast another vote for Wharfedale Diamond 10.7.
The 10.7's are suppose to be even better than the Diamond 9.6 that I once owned. The Diamond 9.6s' were a very smooth sounding speaker that could best be described as full bodied projecting a large, deep soundstage. They were not the last word in accuracy but were extermely musical and performed great with movies too because of that large soundstage. When I finally upgraded, a friend bought the 9.6's and matching center so I still get to enjoy them from time to time. I still have a pair of Diamond 9.2's that I use as rear surrounds. They blend in well with the front three Vienna Acoustics I have now.
If you can possibly audition both the Wharfedales and PSB's, I would encourage you to do so. What sounds good to me, may not sound best to you. If you cannot audition because of lack of availability in your area, then take the leap of faith with the Wharfedales. As Jay1 pointed out, you can't go wrong.
Finally, be on the lookout for possible clearance pricing on the Diamond 10 series as Wharfedale is introducing their new Diamond 100 series as a replacement. I would call Music Direct and One Call and ask when they may start getting the 100's. This could be a tip off that the Diamond 10's you want may start to get slashed in price. Good luck!
Marantz PM15S2 LE, Arcam FMJ CD-17, VPI Traveler V2 with an Ortofon Rondo Blue, Technics SL-1400 with an Audio Technica AT-14sa, Simaudio Moon 110LP, Pro-ject Phono Box S, Pioneer Elite VSX-52, Pioneer Elite BDP-52FD, Dynaudio Focus 260's, Vienna Acoustics Theatro Grand, Wharfedale Diamond 9.2s, REL T-1 & Panasonic TC-P54S1