Hate it.
As far as redemption bookings go at least, it does not appear to do anything better than the old site, it has no new features, and it's more coughbersome to use. If they're going to bother revamping, they should at least add a few features - calendar view or at least the option of moving back or forward one day from the results screen. They also haven't fixed the problem of a flight showing as available in some combinations, when the same flight shows as waitlist only in others.
I also preferred the the shades of blue/grey for fare options and availability, rather than the shades of... ivory(?)
Was it possible to book mixed class fares available on the old site? I thought it only gave this option when your selected class was not available for one of the legs. Eg, if you tried to choose F on a SYD-LHR, it would offer you business on an A380 and First on a 777-300ER. The fact that they now allow F suite redemptions has changed this functionality because choosing first actually brings up first on A380 flights. As I'm not particularly interested in spending a million or so points on a suite, I, for one, preferred the old setup. I guess the only way of doing J on the A380 connecting to F on a 777 is to ring the call centre and lose the online discount...