Is there a distinct performance difference between PX and T5, or is it appearance/labelling? Is there a SIp 2.0 for T5? What's the deal?

Anyone have fact based answer, rather than guessing?
Examples:
PX: @ SIP: http://www.sip-scootershop.com/en/produ ... +_24165500
PX @ Scooter Centre: http://www.scooter-center.com/product/3 ... 66cc+177cc
T5 @ SIP: http://www.sip-scootershop.com/en/produ ... r_24167000
T5 @ Scooter Centre: http://www.scooter-center.com/product/7674962/schwarz