@Demir958 they are quite different IEMs. I haven't heard the SA6Mk2 but I do have the Nova and the OG SA6. If you want Harman Nova is a lot closer to Harman. SA6 Mk2 has much less in the pinna gain region. Nova is certainly better value.
It does raise the question, though, why were you thinking of buying the SA6 Mk2, and why now are you swayed to the Nova in particular. If you want and/or find "normal" the more relaxed upper mids from the SA6, the Nova will sound bright, harsh, thin to you. Conversely someone looking for Harman, the SA6 Mk2 I'd expect would sound a bit dark and muffled; the OG SA6 to me doesn't overly but it has a bit more in that region, while still less than the Nova.
It's just that they are two totally different IEMs so why one and then the other, it maybe indicates you might not know the "why" or what you really like (EQ is great for figuring that one out, before spending $$$).