Well, as there is such variety among particularly seamasters (120, 300, 300m, PP, 1000, SMdV, PO, AT, ...) I find it hard to (not) consider myself a Seamaster person. Compared to this, the Speedmaster aesthetic is much more consistent across the various models, which I all tend to like. As for the true divers, I tend to gravitate to other brands than Omega. Somehow the modern Omega divers (`300m and onwards) don't do it for me, aesthetically at least. The Helium escape crown on the 300m is a little awkward, I find. On the other hand: I really admire the engineering behind the co-axial movement in modern Seamasters.
So summing up this rambling reply: maybe I'm more of a Speedmaster guy, but I find it hard to dislike Seamasters