I have a corotor II on my dish (also a paraclipse) and once you dial it in the Ku is awesome. On my old unimesh 10ft, I started out with a BSC621 and later upgraded to a used corotor II, with ancient lnbs (the C band lnb was an old Macom that weighs at least 2 lbs). It was a definite improvement. Ive since updated both lnbs to PLL and its better yet.
As far as removing the polarotors goes, I would not. You can use a 6 volt lantern battery to change the polarity (a pain in the arse but for testing purposes it should be fine).
View attachment 93104
This pic shows the waveguide in the verticle position as it looks when the dish is at its zenith. You cant see it in the pic but the ku probe is straight up further back in the feedhorn. I don't have any experience with the dual polarotor type feedhorn.
I also have a 36 inch offset for Ku and the performance is similar to the bud, but drops off miserably on rainy days. Overall the bud picks up signals that the small dish cant once it is tuned to the arc. Right now I have t 12180 on 125 w at 83% quality with a tree partially blocking my line of sight. 70% on the Ku dish with clear line of sight.