I'm not familiar with the Quad amplifiers you mention, but have owned Quad 22L2 speakers for the past year (driven by a Musical Fidelity A3.2). I am extremely pleased with them, best speakers I've owned. I've had Mission, Kef and Castle in the past. The bass extension and, most of all, tunefulness of same is wonderful. The sweetness of the treble from a fabric dome tweeter is not harsh like some metal tweeters I've heard. Furthermore, the Quads have a dedicated mid-range driver which makes female vocal so very, very good. Beware though, being rear ported, the Quads are very fussy about positioning. I struggled initially, but settled on about 400mm from the back wall with about a 5 degree toe-in. I've not heard the 21L2's, maybe the reviewers didn't pay as much attention to positioning as I have, and that's why they preferred them.
A friend of mine has Quad Electrostatics (not sure of model, but a vintage pair). He drives them with an old, but perfect, Beard valve amplifier. I couldn't live with them frankly. Extremely sweet sound, particularly the midrange, but limited bass. The imaging sweetspot is millimetre accurate too. Daren't lean across to pick your cup of tea up !!!