I've been using HM5 sheepskin non-angled pads on my SZ2k, but I've been wanting to try some good angled pads. So I got my hands on a pair of MrSpeakers Alpha Pads, and some ZMF Calfskin Oval pads to compare to my HM5's. I'm glad I did. The ZMF ovals went on easy enough, were pretty comfortable, and added some nice midrange and treble plus a bit of width to the sound stage. However, they took away a bit too much bass for my liking. Then I put on the Alpha Pads and the game was changed for me. The mids and highs were a drastic improvement, and the SZ had a wide and deep sound stage for the first time. But what made the pads the best choice for me is that no bass was lost at all, I still felt every hit. Plus, they are far and away the most comfortable pads I've ever put on the JVC. To sum it up, if you can get your hands on them, try the MrSpeakers Alpa Pads on your SZ2k/1k, you won't be sorry.
My JVC with the Alpha pads on, the HM5 in the middle, and the ZMF pads on the right.
HM5 pads
ZMF Pads
The back of the Alpha pads
The inside depth of the Alphas