I haven't yet had a look at the new levels, just the updated ones. Here are some comments with me repeating lots of stuff that was already mentioned by others.
Slaughterhouse: I like this remake very much. But I would remove the sawblades, unless they are necessary. They simply don't fit together with the gore style, in my opinion.
Conundrum: While I like the added decoration very much, I prefer the old name.
Cold Irons Bound: I have two solutions, the first one is nice, the second feels like a backroute.
Exit Stage Right: Very likely a backroute, because I can save 19/20.
It takes time to build: Even though the new style is nice, I prefer the original level. There the layout was a lot clearer and it doesn't have the problem that one may separate a lix from the top to help building stuff at the bottom. Moreover all these sawblades look ugly.
Path to Mahiman: Unique idea, but the solution soon feels very repetitive. So I prefer to cull this one (if we have good replacement levels).
Tower of Babel: This has a glaring backroute by going down at the left edge and not doing anything with the bottom lixes. Otherwise I like the changed style.
Five For Fighting, Lixes in Motion and
Over my head: Very nice remakes!
Now for the culling discussion (going through the list möbius proposed initially):
Digging the air: Agree to cull.
Babylon Fading: Agree to cull (the original version).
When the Levee Breaks: Agree to cull.
A Soulful Bounding Leap: This isn't a bad level. So I would only cull this if we need some more space and have a strong replacement.
Erbalunga: It's a nice level and there are other levels like "Breackout" or "Don't look back" that I would rather cull instead of Erbalunga.
Another funeral: I very much like the solution, but especially with the new digger mechanics the solution became a lot trickier to execute. So instead of removing it, I would prefer to simplify it's execution.
The Last Laugh: Yes, if we have a good replacement for this level among the proposals by möbius, this might be a candidate to replace.
Lixes in Arms: A better level than Last Laugh, in my opinion. Even if we had a very strong contender for its position, the question would be whether to replace this level or another one like "Cuber Replacement".
And finally regarding the reordering discussion:
Parking Garage: It should stay in Hopeless.
I would even pose the question whether it shouldn't come even after "One Step Off", because it requires the same trick. But "One Step Off" hints at the trick, both with the title and the layout, while "Parking Garage" doesn't.
Tinker Tailor: It could be moved 1 rank down, but not more. Note that there have been several NL versions, with this being a backroute-fixed version of the harders NL version.
Lix lies on Broadway: For veteran players who know this trick, this is probably easy. But as far as I know this is the first time this trick appears in the lemforum pack. So a place in Hopeless is deserved.
Rhapsody in Blue: Should definitely stay where it is.
Oh no not again: While the solution is pretty easy itself, it is very hidden. So while we might move it 10 levels earlier within the same rank, it should stay in Hopeless (or be cut entirely).
Eye of the Needle: It is still harder than the first 10 levels in Hopeless, so while I am not against moving it to Hopeless 15 or similar, it should remain in Hopeless.
Conundrum: Feels prefectly fine at its current position.
Death or Glory: I don't think this is much harder than the other levels around it.
Erbalunga: I think mid-Cunning is fine for it, as it has a few solutions (one of them even having one basher and one digger spare).
I agree with all other suggestions for moving levels.