I've attended every San Diego Comic-Con since 2000, and maybe half a dozen WonderCons as well. Before 2000 SDCC I had never attended any sort of comic/fan convention, and I have never attended any convention of the sort that wasn't put on by Comic-Con International.
I say this only to give you my limited experience with convention events, but what I'd consider substantial experience with CCI events...
I don't know what I was expected from SDCC SE. I knew it would be substantially smaller than SDCC, and after the panel schedule came out it became obvious that programming-wise it would be substantially smaller than WonderCon. I personally love attending the large Hollywood panels (I've only missed one Marvel Studios panel in their history, for example), and while Artist Alley is my favorite corner of the convention center, I don't typically do a ton of shopping at conventions: I typically like looking at all the cool stuff being released in the future (like at the toy and studio booths), I have fun with video game demos, and I occasionally like looking at the 2nd-hand booths selling toys I had as a kid in the 1980's for a small fortune (while cursing my parents who made me get rid of it all

).
So I knew in advance we were looking at a much smaller convention: I just didn't know _how_ small it would turn out to be.
The first really weird thing was leaving for the Con every day in daylight; I typically leave my condo in San Diego well before the sun is up for SDCC so I'm used to making that drive in darkness (and getting to the Convention Center garage before Harbor Dr. is closed in the mornings). We got there about an hour or so before doors opened Friday in order to do the COVID verification and pick up badges. W/out ever having done the COVID thing before (obvs), I wasn't sure what to expect, but I thought CCI had a pretty well-run process. We all had to show our vaxx cards + photo ID for verification, and we had to show negative test verification for our 7 year old (finding a COVID test on a specific day that was of the specific type CCI requested as a chore in and of itself). The D-side line was much shorter than the H-side, and as we got close to the front there were people who were coming up through the line verifying before we got to the table: it reminded me of handing out Hall H wristbands, a little bit (no blinky lights, though). I personally think CCI shouldn't had more than 2 people at a table for verification, but w/out knowing staffing/volunteer situation I don't know what CCI's options were. I think it still ran smoothly.
Picking up badges in Hall H, while amusingly discombobulating to me, was incredibly smooth: picking up badges BITD for SDCC was always the easiest/quickest part of the event, and this weekend was no different there. As a Pro we had our own sub-section in the badge pickup, but I did pay attention to the general attendee pick-up and both seemed to run incredibly efficient.
The rest of the weekend was smooth and fun. It was nice to walk around the exhibit hall all weekend and not be shoulder-to-shoulder constantly w/attendees. In fact, Sunday feel down-right eerie how not-crowded the hall was! My wife and I spent more money at this Con than we typically do, with nearly all of the money being spent in Artist Alley: that was a kind of conscious choice (we're both arts educators, and wanted to support artists - many of them local), but there was so much great stuff we couldn't help ourselves! There were plenty of great booths: comics both common and rare; vintage toys; Cosplay stuff; Pac-man Museum where people could demo the new game coming out in 'early 2022' (my 7 year old made at least half a dozen trips to the booth throughout the 3 days). There were even exclusives (Funko; Nanoblocks had a cool Pac-Man LEGO-like set; etc). Everyone we talked to was extremely nice & we made a point to 1) thank 'em for coming out for the weekend 2) compliment the artists whose work we liked (even if we didn't spend money).
Security seemed cool all weekend too. My oldest kid wore a jacket all weekend, and going into the Hall they were constantly being asked to roll up the sleeve to show the COVID verification. My family has been incredibly cautious throughout the pandemic, so we all greatly appreciated CCI's work here. Was the process perfect? Of course not, as others have shown. But I saw security requesting people keep masks on in the lobby, I didn't seen any egregious violation of COVID protocol, etc.
Overall, this was a WONDERFUL weekend! Comic-Con Special Edition was a great way to dip our toes back into the Comic-Con world with smaller crowds, smaller panels, smaller exhibit hall representation, etc. but still have fun. Going into the weekend I of course had my list of panels I had to see, off-site stuff I wanted to check-out, Exclusives I wanted to get. And I accomplished everything I wanted to. I even got lucky with the 'Box of Deciding' at Funko on Sunday, complete with a relatively early time (10am), and got the Funko exclusives I wanted (with the bonus of being able to get a Grogu Macy's exclusive: something I didn't know existed until Thanksgiving morning, and something I didn't know would be for sale at SDCC SE until Friday am). I even went to the Comic-Con Museum panel on Saturday and experienced an SDCC panel with Eddie Ibrahim (long-time Director of Programming who is a Hall H mainstay) on stage to give me the ultimate "I AM AT COMIC-CON!!!" experience

I got to meet Jim Starlin, and get my copy of 'Death in the Family' #3 signed by him: a comic that I've kept since I was in middle school, and represented the fruits of my very first experience with democracy, when I did indeed call in to DC's 900-number to vote to murder Robin (Starlin said they were all convinced at the time that "Batman fans were ghoulish enough to kill off Robin"

).
We had a blast, and I sincerely hope that all of the permanent signage CCI had for Comic-Con Special Edition indicates this will be a permanent late fall event. If my schedule works out, I will excitedly return to this event, and I of course can't WAIT for Wonder-Con April 1st, and SD Comic-Con in July!!