I can't speak directly to the L820s, but I am using L830s for mains along with L810s for surrounds and an LC1 for center. I would rate them as good to excellent for home theater in their price range. For music I have had them since Xmas to evaluate the L830s vs a vintage pair of JBL L1s circa '93-95. For anything recorded recently the L830s hold their own mostly for jazz and classical (poorly for classic rock). In general though they don't hold a candle to the older L1s. Keep in mind the L1s were made before HT was even popular and music was their forte'. I now use the studio L series for multichannel only and have the L1s set up in a different room for stereo (music) only. If you don't like a "bright" style of speaker design, the Studio L series may not be for you, but they do handle multichannel formats quite nicely IMHO.
Perhaps the additonal driver in the L820s may make a difference. Oh I forgot to mention, they are beautiful especially in cherry.