I've been thinking about similar things myself and I would have to agree with those rankings personally: 2 > 3 >>> 1
Imo Bordello 2 is easily the best of the series so far and I'd go as far as to say Nyl's best work to date. Love the Drow twins, love Darcey, the video feels perfectly paced, good mix of porn content with story content. I like some of the transitions in this one, they feel creative - the cut to Calarel complaining to the new girl outside of Darcey's room, the point blank cut to the first blowjob scene is funny. I wish it was longer but that's a given.
Bordello 3 is pretty good. I like Lyria a lot, I like that it's so long with both a lot of narrative content and a lot of pornographic content, but I am not a fan of the Tiefling client. Something about her just throws me off, I think it might be the eyes, they just look weird, though I'm not big on Tieflings in general. And while I think Nyl usually has a good ear for picking appropriate voice actors, I don't like the Tiefling's voiceover, especially contrasted with Lyria's VA who I think did a great job. Nyl said that a reason B3 took as long as it did to come out was because he had trouble getting the VAs to submit their work and one of the voice actresses entirely ghosted him. Pretty sure Lottie and Calarel have the same voices, and the Gith girl had like 1 line so if he needed to recast her it'd be easy, so it was probably one of the stars, and I'd bet it was the Tiefling's VA over Lyria's, meaning the one we got wouldn't have been the initial choice. If I'm correct, I don't mean to disparage her, and big props to her for stepping up but I did not care for her voice in this role.
Bordello 1, I don't like all that much. I'm hesitant to call it outright bad, it has redeemable elements, but I don't find myself returning to it often. I like the Orc a lot, but the Elf client is not to my taste at all. Between the short hair and flat features, she feels almost too close to like a femboy/trap to me, which I'm personally not into. It veers too close to futa on male territory for my liking. The only scene I've viewed repeatedly is the first immediately after the intro.
I have high hopes for Bordello 4. Excited for Calarel, and I'm honestly good with Rose - her face might be a little weird but her body is totally fine by me, if anything Lyria was his attempt at a chubby girl already and from all the previews of her, Rose doesn't seem to be any bigger than her. If the still image previews are anything to go off of, there will be a lot of scenes, and they all look good. Nyl said he doesn't want it to be as long as Bordello 3 and he'll try to rein it in and keep it shorter, but knowing him (and how long its taken so far), that won't happen and it'll have a nice long runtime. And the non-porn parts sound interesting too, with the premise of the animation, all the new assets he's made, Darcey reappearing, maybe even having music from a composer as he mentioned.