Ha, as far as GAS is concerned I am quite the failure when it comes to film photo gear. I have owned just four different cameras since 1980 and not too many more lenses during this time. For that matter I’m also a failure as far as photography goes in that I have never been a high volume shooter (not even with my smartphone or the small digicams I have often carried with me). Perhaps were my creative vision better this would not have been the case.
I've never been a high volume (film) shooter till the trip I took last year. Which somehow, has made me to bump up a bit my film shooting.
I left out the un-RF part of looking for a 645 like a Pentax 645. Half frame is cool nowadays! But the auctions went expensive so back to the cycle of budgeting for more film instead (or travel). AS per the latter, I have been bitten by the travel bug and film budget does compete with a weekend somewhere in Europe locally.
I like how Retro-Grouch has some on points in the discussion
E6 is a different (and crankier) mindset, somewhat akin to shooting collodion for tintypes, or doing daguerreotypes. Of all present processes (except perhaps instant films), it has the closest indexical relationship to the subject before the lens. For me, working as a documentarian, this is important from a conceptual standpoint: knowing the film used, a viewer can look at the slide and know that this is what the subject looked like, as translated onto that film, and by extrapolation in "real life". And from the standpoint of my own approach to process, I like the discipline of being forced to shoot with the demanding technical precision that slides demand. I'm more than a bit OCD, as you may gather!
Slide films do give a different rendition from print films, though I would think that a C41 negative, containing as it sometimes does more information due to its greater latitude, can be made to look much like an E6 image.
Something that might be a stupid rebuttal: The pros did it back in the day. Seemingly, I was anyways too young to actively being involved, Slide film was almost everything for publications and media. I like seeing some, now 20 year plus old images and recognizing that they were shot on slide film. Actually, I don't quite get the "it looks like digital" except for the grainlessness. Depending on exposure, slide has a specific Punch to the primary colors and specially reds.
Then also, up until the 80s where slide was about the main color media for consumers, many did manage with roughly sunny 16.
Back to our contemporary times, I think slide has a certain fear factor compared to Color neg because it cannot be overexposed 3 stops without much consequence. Also a reason why I liked Provia was to skip scanning inconsistencies by labs. Then I'd outright skip scanning, and just view the 6x9's on a backlight with pure enjoyment.
Actually I do have a couple nice rolls of Astia 35mm that have been frozen since I got them pre-pandemic, aside of shooting one for fall 2019. So it has been really long since I did 35mm slide. 120 I do, but you also bring up the great point of ISO100. I also live up north and it's worthless handheld for half of the year.
As of the processing, batching up and DIY might be a good way to go forward. The newly launched ADOX 3 bath kit can be simple, I had no problems back when it was Tetenal. For me it has been a bit easier, as we did a local photo club wide event to shoot E6, bought a kit and agreed on a common developing day for a season; so a few members could have a single roll and that makes it worth it. Last spring we did use a 6 bath kit, and despite quite some care we got some weird shifts so got a bit more respect to the process.