The Rollerblock Jrs work surprisingly well in my system as well. Though I only have them under my phono and under its power supply, while I have a 1" steel plate under my amp. My rack is 1 1/4" high quality birch plywood, which is sonically dead. And, as I've learned, not dead in a good way. But it seems the Rollerblock Jrs perform best atop a dead substrate (like the symposium platforms), so the plywood works well in conjunction with them. And I found the Rollerblocks better than other (far, far) more expensive footers, including those particularly popular on WBF. It was really remarkable at first listen. The appropriate analogy between components directly on my rack shelves vs using Rollerblocks in between would be 8-bit color vs 24-bit color. You just get more - in a very natural / realistic way. I was so surprised at first listen that I sought out reviews of these things to validate what I was hearing. I found one that nailed it (from a site that I never otherwise read) ...
"Rollerblocks decompress the internal musical structure and release more details, subtler inflections and finer gradations of tonal colors" -Srajan Ebaen
^ This. This was exactly what I'd heard.
On the flip side, I've heard some complaints that Rollerblocks make things like bass too tight, transients too sharp. It doesn't have to be the case, though. Hard to believe as it is, the bearing quality actually makes a difference there. There are some very good quality, inexpensive bearings at McMaster Carr that don't, to my ears, sound like the Symposium bearings. I hate going down the path of evaluating bearings ... but it was cheap and easy to do, and I stopped there. I've picked up numerous sets of Rollerblock Jrs used on Audiogon now. The investment is so minimal compared to the performance I get from them. Recently, I picked up a set of HDSE to compare to my "standard" Rollerblock Jrs. Haven't tried them yet, but will sometime soon.