Get yourself some headphones that are great on detail and dynamics and are not warm. The AKG K-701 fits the bill, but it's not the only one. Stay away from the HD-650.
I listened to this amp again on Saturday and compared it with my BC SBH using K-701s. It did very well. Sugden products are all first-rate and all are very musical without being colored. This is NOt a high impact amp. If you are looking for a head amp that sounds like Dynaudo speakers (i.e., sounds good with banging garbage can lid type music) this is not the amp for you. It is detailed, refined, balanced and smooth, but with a nice dose of PRAT. It is Not forward. It is Not bright. It is Not rolled off on the trebble. It does Not have bass boost in the frequency response. It is an amp for a music-lover and it deserves a good source and headphones even at this price.
I do own a MAD Ear +, and I like it very much. But lately I have moved back more toward SS amps. due to their greater balance, better detail and lower distortion (at the loss of emotion). The MAD Ear+ is, however, another fine choice in the same rough price range and it is also quite neutral even though it's a tube amp.
One last thing, when you read a review, do understand that it reflects the user's sound preferences. These are usually not stated and may differ markedly from yours.
Here's the music I played with the Sugden and my SBH on Saturday, including parts of: Boxer, The National, Mahler's 5th Symphony, Black Sheep Boy, Okerville River, Transistor Radio, M Ward. All of them sounded great