Reggie is NOT worse than Muss. Reggie's teams are competitive, and the season Muss was here, the team never had a chance.
We're just talking about D, or at least I was. And yes, Reggie's teams are playing worse D than even Muss'. I'll list the most obvious stats, since stats are what I'm basing that statement on. The numbers in parenthesis are the Kings ranking within the NBA in that stat.
..........FG% allowed..........3pt % allowed.......pts allowed
05-06....45.4 (16th)...........35.1 (8th)............97.3 (16th)
06-07....47.2 (25th)...........36.6 (22nd).........103.1 (23rd)
07-08....46.6 (21st)...........37.3 (24th)..........104.8 (23rd)
08-09....47.7 (29th)...........43.1 (30th)..........104.8 (26th)
So Reggie improved FG% allowed slightly during his first year, relative to Muss -- but is doing worse than Muss did this year. With the exception of that one slight hiccup, all of our defensive stats have been steadily declining ever since Adelman left.
EDIT: insomnia gets us the remaining defensive stats. Not as clearcut, since one can still get a lot of steals and blocks while playing weak D, but... for completeness, here they are. They show as much about roster changes as about coaching, I think.
............Rebounds............Blocks................Steals
05-06....40.6 (18th)..........3.7 (25th)..........7.4 (9th)
06-07....38.9 (30th)..........3.2 (28th)..........8.2 (3rd)
07-08....40.1 (29th)..........4.1 (27th)..........7.9 (7th)
08-09....38.0 (29th)..........4.1 (25th)..........6.8 (22nd)
I'm still content with Reggie, despite this, since he's mostly shutting up and playing the kids. We could maybe use a new defensive assistant, though!