I grow both x Tiveyi and a couple of the maxima-dark x veitchii highland striped referred to here, and they are very similar of course, but slightly different in shape and colour of the peristome. Given that both come from various clones, there will be differences from the same cross from the seed mix. A friend had a couple of maxima-dark x veitchii highland striped he got from Geoff, and they show slight differences from each other and mine. They're all attractive hybrids, but do take up a lot of space (like veitchii once it gets going).
Gus, to answer your question, there is a bit of contraversy about maxima-superba and what it actually is. The couple of photos I've seen of it look like a reddy-brown variant of maxima, and it could be a lowland variant, but I'm not sure. The maxima-dark variant Geoff used in his cross is a dark chocolate highland variety.
Hamish
