I've got one of them barlows now, and it is a beauty. My old Shorty Plus got the sack the day I tried the 2" barlow. You want negatives, here: There is noticeable light scatter when barlowing high contrast eyepieces like TV Plossls and UO HD orthos. The views are still awesome just a little diffuse scattering of light is noticeable. That's about it.
On the + side, my 19mm Panoptic in the barlow makes for a fantastic 9mm wide view EP, very sharp on-axis and good sharpness to the very edge (and beyond
, 6 stars in trapezium edge-to-edge no sweat).