There is a fellow in the UK that plays in an Ozzy Tribute Band....he had gotten the TS9 mod from us, then ordered a SD-1. He swears by the SD-1 and even ordered a second. He says it has a better tone for his taste and style. Truthfully, he convinced his buddies and they ordered 4 more! So, I guess they are happy with the tone improvement. In the case of the old MIJ SD-1 pedals, the filter in the power supply is more than would ever be needed for today's supplies and it can be removed adding a lot to the volume and headroom of the pedal. In that case it makes a very nice difference!
Ya know, I had a 777FP the entire time I went to college and towards the end, being broke and amazed at the ebay prices let it go...what a shame! I sure miss it these days! ;-(