Active FETs vs. Step-up phono stage designs


I've noticed quite a few threads on A-gon discussing step-up transformers recently, and it got me thinking of the different applications in the phono stage design. I'm curious of the advantages and disadvantages of designs that employ step-up transformers vs. active designs with FETs, especially in tube preamps. Examples would be the new Manley Chinook vs. the Rogue Audio Ares with its custom Cinemag transformers, or the highly-regarded Andros, which also went the step-up route. I'm thinking of upgrading my solid stage phono preamp in the near future, and would like to hear your opinions (and I know we have a few designers posting regularly) regarding this subject.

actusreus
The MAT02 certainly lives up to AW's opinion of it in the context of my preamp. I have two extra pairs, just in case. (As you know, the MAT02 is a dual section device, so one of them suffices for each balanced channel, and the section matching in terms of transconductance, etc, is way better than one could hope for in a dual section tube, plus it stays that way over time.) Everything else downstream is tubes.
The discontinued MAT02 is replaced by MAT12.

http://www.analog.com/static/imported-files/data_sheets/MAT12.pdf

Like Lew I use this at input of phono in the bottom of a hybrid cascode. It provides huge gain, low noise, and great sound.
Thanks for that URL, Dave. I did not know about MAT12. I wonder if it is equally suitable to our application, compared to the MAT02.
Lew, another hobbiest has used MAT12 interchangeably with MAT02 in this application, so I don't think there is any issue.
Have you noticed the pricing on this part? $15 in thousands quantity? No wonder folks are being driven to op amps.