Onix SP3: What speakers are you using?

Hello again.
My love affair/obsession with this little amp continues.
My tube compliment and the HiFi Tuning fuses are burning in nicely. I am really, really enjoying this amp, this hobby and the three pairs of speakers I own. That's the problem: I have three sets of speakers I absolutely love.
I'd like to hear from other SP3 owners what speakers they are using, why they like them, and why they pair well with this amp.
I look forward to hearing from you all. I always learn a lot from your responses.
in a near field ( 10x12 room) i am using the new harbeth p3sr to excellent effect: sufficient and clean bass, with the harbeth mids and upper mids. sounds much 'bigger' than i have any right to expect. just enjoying the music.
Thanks for all the great info.
I am amazed to hear the SP3 can power the Harbeths. I am glad to hear it though. This opens the doors to new possibilities for me.
If you haven't heard Rega speakers I highly recommend you do so. For the price, the sound is incredible. Hey I own two pairs and I can't decide which I like better: the Rega R3's, Rega R5's or the Onix Ref 1 Mk 2's.
Heck, I just swap them out every month or so and I really enjoy them all.
Please give the Regas a listen. The new RS series are said to be even better.
I also love this little amp.

For about two years I've been using some rehabbed/modified Dynaco A25 speakers with mine. These vintage Dynacos replaced a pair of AC Sapphire III LE speakers in my system due to their (comparatively) amazing synergy with the Onix. Using them with a Mirage subwoofer (line level) and it was easy to get a seamless blend.

I have used many speakers with this amp and most sound good. My two favorites were the Usher be718's and the Sol 5's. By the way , which HiFi tuning fuse do you use. I know it is an 8A/250V. But is it fast or slo blow....