They came out last week, the DU340 is the TTXGP shock for the Panigale replacing the DU930 TTX MKII model. The TTXRT models are being made for lower-spec bikes, not the Panigale. The TTXGP has a new compression and rebound needle design giving it a wider adjustment range and supposedly it's more precisely machined for less variation between shocks. Also has a new main piston design for better optimized flow. So overall I'd say it's small changes incorporating the latest things they've learned from racing in MotoGP. Not something that you'd probably see people upgrading from the MKII to the GP for, it's small improvements.