The 4310 is a noticeable improvement over the 3808 and I wish I had waited before purchasing my 3808. htnut has highlighted the major differences and if the 4310 wasn't ~$1000 more than the 3808 was when I bought it I might own a 4310 already. As the saying goes good things come to those that wait, and wait I shall.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70