One good reason
One good reason.... I've seen T2 owners DESTROY their outdrives due to poor design.
If you look at the T2 design the outdrive has zero support on the outer edge of the outdrive - therefore leaving it exposed to being ruined upon impact with a wall.
(I just saw a guy at my local track do this 2 weeks ago during practice - and he was done before the race even started... he said it was his 3rd one....within 6 months)
If you look at the RDX design, the outer edge of the outdrive is supported by the bearing.... you'll never have the problem the T2 has with this.