Manley Neo-Classic500 vs VTL MB450


Anyone compare these two amps side by side? Or has anyone given a good listen to the Manley alone? Ive read a lot about the Neo-Classic 250 but I have not heard anything about the 500. Does the 500 use el 34s or 6550s? Any input would be much appreciated as I am about to purchase new amps and I know I definately want to go with big tubes.

Thanks
braro
What are your speakers, by the way? Do you absolutely need 500 watts? My opinion is based on having and living with VTL 750 and the 250's here for some time. FWIW the inside scoop is that the EL34'd Manley will give more midrange liquidity and inner detailing/beauty than any 6550 design. It may not be completely neutral but is stunningly beautiful and lush without being fat or slow. Piano has never sounded more real than the 250's on WattPup7's. Bass was slightly deficient in triode, but not a big deal as you can switch to linear for more juice. An embedded Manley person once told me that they'd take the 250 over the 500 anyday FWIW.
Owl

Speakers are Vandy 2CE Sigs soon to be 3A sigs and room is 14'x 35'x 8'tall with speakers on 14' wall. I am also running (2) 2WQ subs. Current amps are VTL MB 125s. Even with the subs I just cant seem to get much mid bass. Tried speakers in all different locations.