I know very little about Thoth, but here is my 2 cents.
I love Liber T - Andrea Serio's art is fantastic. In some ways it gives me the impression of being something more than Thoth, but in other ways, the lack of semi-plain pips, means that maybe it is less flexible as a deck. I personally love the minors of Liber T. Either way it is one of the best tarot decks in existence imo.
The Hermetic Tarot isn't a Thoth Clone - but it has a raw edge, character and existentialist madness to it that is sadly missing from the other two Golden Dawn decks - which I couldn't bring myself to use personally even though considerable effort has gone into their creation.
Tarot of Ceremonial Magick - a mixed bag. Some of the artwork is quite good, but for the large part the majors are a bit too cutesy for my liking. The minors are ok bar the odd moment of silliness - but the courts are not very good at all. They feature the same line drawings for the 4 characters in each suite with the relevant object attached to them - but never quite in the right place so the effect is not convincing. There aren't that many court cards and given the simple nature of the court drawings, it couldn't have taken Lon Milo more than a day or two more to draw proper court cards, each one unique. Disaster! I do like all the Enochian tables, Hebrew and Planetary Symbols, and Tattwas included - not that I would know what to do with them as yet. However I get the feeling that I couldn't use this as any more than a study deck - the art would just put me off too much. I would imagine that taking a tarot like BOTA and adding in the tables and symbols from the ToCM myself would be much better than the ToCM itself, giving the best of both worlds. ;-)
I think the Via Tarot is a mixed bag. The courts are really fantastic - the best I've seen on a Thoth-style deck. However, the old crone figure in the minors is not that well drawn imo and ruins the overall effect of the deck for me. I like the fact that the deck isn't cutesy though - which is something.
The Rosetta Tarot - an excellent deck. However, not sure what it is exactly but it feels too cutesy for me. Maybe the lack of pen and ink lines in the characters and animals is to blame but it makes them look devoid of any venom. Some people say this is why they like the Rosetta more than Thoth but for me it is a bit of a show stopper. Also I feel that whilst MM is a fantastic artist, the small sizes of the original paintings limits the deck quite a bit. If she had painted larger paintings for each card like with her latest tarot and scaled them down more, it would have looked much better. As it is, her latest Tarot looks really professional but the Rosetta looks more crude in its style. There are reasons for the way she's done it but I think she missed a big opportunity there personally. Also, the RT seems to lack the depth of the cubist backgrounds of Thoth although a few cards have rather good backgrounds.
Tarot of the Spirit is a bit Thothy, and I think it's very good in places, but overall it lacks the umph I'd really look for in a Thoth 'clone' or Thoth inspired deck.
