I also use a headamp and do so very happily. I find it quite flexible (it has two gains and a pass-through, and 4 different loading choices). It easily beat my previous best SUT, that said it cost a bit more than the SUT did, and I have never tried a SUT with the reputation of the S&B TX103 (i.e. one of the best ever made).
What Step-up transformers are best value?
I have recently bought a VDH Black Beauty cartridge. It needs top-flight SUTs. I'm currently using Silks, which are very good. I have also tried the S&B TX103s (lent by a good friend), and they are noticeably better. Their price, however, is prohibitive (£1400). Anyone know of any serious bargains out there, which are up there with the Tx103s?