Those look incredible compared to the current SD releases. It will be interesting to see how the later seasons shot in California (with more FX work) compare. The X-Files was probably my favorite show, but those later seasons were tough to slog through as it became more "epic". The whole style and pacing of the show changed and I didn't enjoy it nearly as much. I haven't rewatched it in a long, long time. However, I will probably buy this set (when/if it comes out) if only to get my favorite seasons and episodes and to promote the HD releases of my other favorite TV shows.
On that topic - the wife and I have been rewatching Stargate SG-1 from the beginning and despite many alien worlds looking a lot like the Pacific Northwest, I really love the style of 90s TV shows filmed in Canada (there were so many!). There's just so much atmosphere in the outdoor shots, the landscapes are beautiful, and the lighting really sets the mood in a natural way (without post processed CGI tweaking). Truly dark night shots, subdued day shots. Perhaps it's just part of the grunge era, but the shows really have an earthy feel to them... slower pacing, too. So much more than that, after watching modern shows I really appreciate NOT seeing "dirty" camera work. No shaky cam, no absurd focal changes, no wobbly closeups. Many of the CGI shots are terrible by modern standards, but at least they serve a purpose by assisting the storytelling and aren't just eye-candy filler (they couldn't afford it!). By no means am I saying that modern TV shows aren't good, just that they could learn a thing or two from that decade. /soapbox