I once used a pair of Wharfedale Diamond 9.1 75th anniv. Edition with Rotel RCD02 cd player & Exposure 2010S integrated amp. Now it has been replaced by Tannoy Mercury F1 Custom.
(the Diamond anniversary enclosure is made from real wood veneer)
Comparison between Diamond 9.1 & F1 Custom:
I found the Diamond to have more extended high freq. than the F1 Custom. However, the Diamond has more colouration, the sound is nice and warm, but not in a good sense, these nice & warm things seem to be fabricated, as opposed to an honest and realistic sound. In other words, to me this loudspeaker really has its own colour, which are nice & warm, thus accuracy is definitely not a strong point here.
Is it because the designer aimed to create a loudspeaker that would appeal to everyone? Initially this diamond appealed to me, thats why I bought it in the first place. But after 2.5 months of quite intensive listening (6 days a week, 2 to 3 hours per day), I come to these opinion.
The Diamonds imaging is also significantly less vivid compared to the F1 Custom.
I also noticed some upper bass emphasize with the Diamond, where the upper bass sounds too thick. This improper thickness seems to have negative impact on detail and transparency, as bass and mid definition is another weak point here. The F1 Custom might seems to have weaker bass than the Diamond, but it actually can play low notes far better. This is obvious with piano repro in many recordings, where the F1 Custom still able to present some low notes with good definition and impact, but the Diamond falls short by a considerable margin. For drums repro, the F1 Custom does it with good realism, from the cymbal, snare to the kick drum, while the Diamond cant help to present bloomy, unnatural bass without solid image. But for even lower notes, both speakers do not have such extension, its normal due to their small size.
F1 Custom throws big and stable soundstage, the width may exceed physical boundaries with some recordings.
So for a speaker under USD500 (or 300 pound), I find the F1 Custom is really good, with the following characteristics:
1. Minimum colouration : honest sound, realistic reproduction from the sonic & music point of view
2. Neutral tonal balance: not warm but also not cool, sounds like the frequency response from top to bottom is quite linear (maybe anybody has measurement data to correct or confirm my hearing on this?)
3. Detail, transparent and focus, but not drawing attention to itself, the attention is on the music, enable me to deeply listen to the music.
4. Quite revealing of recording material quality/character
Before purchased the F1 Custom I auditioned several speakers: PSB Alpha B1, Paradigm Atom, Usher S512, B&W 686 & Epos ELS8. IMHO, I consider the F1 Custom to be better, overall, than the others, eventhough the comparison were not apple to apple as different electronics were used in each auditioned. Compared to the F1 Custom, I noticed that the PSB produces deeper soundstage, but less natural timbre of mid and high freq. The Paradigm sound is detail and has good clarity, but the midband timbre is not satisfactory to me. The Usher has more holographic imaging, but the mid sometimes has shouty character, and the high has forward character. The B&W has bigger bass, but presenting music with not enough life and soul (the problem is similar with ELS8). The Epos has more extended HF, but Im not attracted to its rather thin midrange character. I suppose personal taste also had some contribution to my choosing the F1 Custom.
As for the Diamond, I dont belief it has a strong position against the other speakers mentioned above. Its quite strange that the Diamond receives so many good to very good reviews anywhere, including What HiFi magazine, UK, who gave it 5stars (F1 Custom also got 5stars review. But in a group test of 5 or 6 speakers, among which are the Diamond and the F1 Custom, What HiFi chose F1 Custom as the winner). The Diamond is more like a 3stars performer to me, I would not recommend it.
Prices (US retail price): the F1 Custom is USD140, the PSB USD 280, and the others are above USD300 (the Usher is above USD400).
I belief the F1 Custom is an underrated performer, partly due to its low price, where some recommendations I read is just to use it in a mini hi-fi system. Actually it strongly competes against USD 250 450 (150 300 pound) loudspeakers with a real chance of winning. For anybody whos looking for under USD500 loudspeaker and interested in the Diamond, I seriously advise you to re-consider your interest, give both the F1 Custom and the Diamond (along with the other speakers mentioned above) a thorough audition before make any decision.
Ha Ha Ha. Nothing is too 'budgety'. The reason I did not step in is basically I saw a healthy discussion going on between people who know the products intimately in terms of their capabilities and prices. 
