Good to hear you are happy with it so far, I was confident you'd be pleased. Pioneers were generally well built of those I've seen up close and under the hood (admittedly not near as many as Sansui) but share your sentiments about cramming a lot of stuff in on the Pioneer receivers, rather than start with a bigger chassis, which they did for fewer models than Sansui near as I can tell.
One thing I didn't much like about Pioneer builds was the extensive use of wire wrapping for inter-board harness connections, rather than pluggable connectors - or even soldered points- as Sansui frequently used. Yes, wire wrap is secure so connection quality isn't an issue, but ease of serviceability is impacted by that approach. A small complaint really, but something I noted.
My favorite pioneer has to be the SX-828 for overall quality, sound and looks. An earlier model (71/72 I believe) that was somewhere between a Sansui 2000X and 5000X power and feature wise, but exceptionally good in almost all respects and I have to acknowledge that here. The SX-2500 is really neat with the auto tuning and remote (I have an Allied 498 here based upon the SX-2500 with a few minor feature and cosmetic tweak but sans remote) and it is a very good receiver, but the sound doesn't grab me the way Sansui does.
The two color knobs (black with silver skirt) on the 2500 never looked quite right to me for some reason. Yes, subjective, I know. FWIW, the Aliied has knobs unique to their line, not the Pioneer style knobs. Some effort was made to conceal its origins, there are many clearly shared parts however.
I think you'll find an affinity for Sansui (for the sound if nothing else) in the long term. Existing preferences and biases can be hard to shake, but I've seen more than a few converts who were bitten by the Sansui bug. Which is not to say you'll forego any further interest in Pioneer, and there's no reason you can collect both, outside of budget constraints and physical space to stack the gear.