The 05 is a od board too and thre are much more similarities that differences compared to the 07 70 XTV. However, the XTVs are really an evolution of the shape. Regarding the 70, I don't feel it is sinificanty faster or earlier planinign (rather simlar to the 04-06). But turning is better. Especially, the top turn is now much smoother and easier and the faster you go the more noticeable this is. The way this was done was with a refned v profile and slightly adjusted rocker.
08 and 07 are rather similar when it comes to the 70. The 08 is slightly thicker (+2 liters maybe) and the ouline is lightly adjusted.
The insecurity prblem you felt on the 05 70 is largely an adaption issue. Wle you will never get the same direct rail connection as on an Acid, the EVO 70 still handles big bottom turns very securely when you're used to it. The main trick is starting the bottom turn with some mast foot pressure. Ie, drop in, settle the board by some mast foot pressure and then go about turning pretty much how you like The aster the wave, the more important it is to keep some mast foot pressure throughout the turn. This becomes second nature after a while.
Bottom line answer: The 05 is stll a rather up to date shape, but if you surf faster waves, the 07 is certainly an upgrade. The 07 70 is my fav EVO so far. I'm on Maui ow. Its the only board I brought.