I have a shelter 501 in a box, on the shelf, with all the other retired but still good audio paraphanailia I am collecting. The shelter was great, until I upgraded my phono stage. A couple xmas's ago I gifted myself a fosgat(from santa). The next morning I hooked it up, turned it on, cued up Hungarian dances....anticipation became lunch bag let down:(.
Instead of giving up on the well regarded fossgate, I bought a nice used zyxs airy 3( right here). After installing I repeated above process...and was happily blown away.
Sadly I don't know the r100. But I am planning to have santa bring a new airy 3 this year:).