I had a similar query to yours a few months ago. I have a 1200GR with fluid damper.
Have tried the ATVM540ML (RigB upgrade) and when I realised I felt something was missing due to the voicing of the 540ML, I nearly purchased the AT33PTGii but later decided to purchase the AT33EV. It went into a vintage AT SUT and then MM input on a rotary mixer.
My experience:
Whilst the AT33EV has a less advanced tip, I prefer it overall to the 540ML. The 540ML wowed me in terms of detail retrieval but it definitely had a sound signature I wasn’t used to (came from a Denon DL-110, so warm and a huge soundstage) and it sounded quite thin at first, then more balanced as I racked up more hours on it but I still felt the bass overall was lacking and sound stage was narrow. It was quite bright even when trying super short cables to keep capacitance low (supposedly requires <100pF). Could just be that it allows you to hear higher up the frequency range with its tip, so sound is perceived brighter but I think it's just the way AT voice this cart in particular as I've read the AT33PTGii is more neutral and less bright despite sharing the same ML tip.
I also play a lot of used/pre-loved vinyl and the 540ML was very revealing of any damage presented on the record despite some comments I’ve read saying it will dig deeper past previously cut route of less advanced styli from previous plays. That is not to say it is a slouch by any means, it excels especially on clean, pristine vinyl - there’s no doubt about that. You can audibly define each instrument’s sound clearly and even though lower bass was tight and narrow sounding, it was deep and hit quickly. Definitely heard my collection in a whole new way, which was fun!
The AT33EV is a really nice looking cart with a highly polished nude elliptical on a tapered "duralumin" cantilever. Maybe it’s just the MC aspect but the music presentation is way more balanced, sounds more involving and less harsh/quick and sounds more natural, especially on vocals! You are losing a slight bit on details and sharpness compared with the ML, but music actually sounds like it’s being played from vinyl (540ML sounded like CD on some records...) even though it glides over damage with ease and surface noise is reduced (so it worked in my particular use case of used vinyl, nicely). Some users complain it’s too veiled but I didn’t find this much of an issue being appreciative of thick, strong bass so it immediately won me over in that regard. Soundstage is also much, much larger. The 540ML sounded like certain instruments were panned hard left and right but very narrow. The AT33EV on the other hand clearly panned high-up left/right and down-low left/right, like sound filling a nice big room, if that makes sense!?
I’ve now moved the 540ML to a 2nd turntable (1200MK2) and the AT33EV is on the 1200GR (main driver). It’s nice to go between them based on the different records
Tried my best to describe the differences in a musical sense as I know that is really helpful to some when trying to decide on what cart to go for. I will try the AT33PTGii potentially in future but I think I’ve realised there is such a thing as having too much detail at the expense of musical enjoyment…especially when vinyl doesn't sound like vinyl anymore! Hence the reason to skip it and going for the AT33EV. More than happy with the 540ML for details when I fancy it.
As always, YMMV as it’s all dependant on your system and your ears (mine being on the much warmer side and still preferring the AT33EV overall)
