yeah, the door on those models is purely cosmetic, unlike that of the VSX-D1S.
those cosmetic doors seem to be attached to the front bezel's underside via a decidedly flimsy, breakage-prone pair of plastic hinges, ala the somewhat more robust ones on SONY's STR-GX80ES and GX90ES;
STR-GX80ES



STR-GX90ES



fairly nice receivers, in their own right.
still, the VSX-D1S can handle speaker impedances at least as low as two ohms, and PIONEER sure didn't make a big production of that fact, and then slap it straight onto the front panel.
the VSX-D1S has a certain degree of inheritant self-confidence about it, much like PIONEER's own 1970's-borne former logo; a certain swagger, that, to me anyways, suggests that it is more than capable of taking care of things, and it is to be taken quite seriously.
product design such as that, is, IMO, fast becoming a lost art in the CE industry...