The Silver Rock is amazing. Its one of two components I have yet to be able to part with.
If from a technical perspective, you have no system matching issues, a transformer based volume control is often a straight up eye opening experience the first time people here it in a system.
As for actives -- there are some rather impressive ones out there. But those designing them usually have different perspectives -- some are purposely looking to 'give you something' with it -- some are particularly trying to maintain the elusive neutrality.....while adding an entire different interface and active stage between source and amplifier.
Sometimes that adding something is nice, sometimes its not, but its really worth a shot to get a TVC and see how it works in _your_ system.
The complaints I've heard most of the time really sound like poor system matching (technical), while occasionally I hear what sounds like poor system matching (synergy) -- where you see a system and go, why on earth would you want a source that horrible passed direct, and to an amplifier that will sound horrible? In those cases, I'd highly suggest an active, a colored active, and something that functions as an embellishment engine.
At the same time there are some folks who clearly know what they are talking about, and did not like the effect -- just a preference.
I'd see if you can get one or the other, and whether a visit to a dealer, or someone in your area, try them side by side -- it won't be something where you'll be trying to search to find the differences....
Leave me an email if you would like further ramblings -- I tend not to reply to threads once they disappear from the 'New Today' page on Audiogon..