I dont know really. From my experience, I've had an OCZ Agility 3 - which broke in 2 months, and an OCZ 750w PSU thats kept on going for 3 years without any problems whatsoever, and it does feel really well made if I'm honest. Tbf, I did only buy it because at the time I though OCZ were really good...
But I admit that comment may have been a bit harsh, and the new Vertex 4s may be really good, but they've been out a month, and I'd want to give it at least 6 months to see if they develop problems before I got one myself. It just seems like an unneeded risk to me, it's not like they're going to be a million times better than an M4, so I'd rather just give them a miss.
I do agree that spec wise the Vertex 4s do look really good, but so to did their Agility 3s, and we both know how they turned out. I just think it is too soon to tell whether they're worth buying, and because of that, I'd still want to avoid them.