There is one main difference between the plossl & SuperView you mention, the former is a 1.25" EP & the latter is 2". Unless you have a 2" diagonal on your SCT you'll be limited to the 1.25".
The difference similar focal length EPs will have in the barrel size is how wide an Aparent Field of View (AFOV) they can go due to the size of the barrel. The wider the barrel the wider the AFOV can be for a long focal length EP. With these two you mention, the plossl's AFOV is a small 43*, the SuperView's is a hefty 68*. This in turn means you'll see a wider patch of sky in the SuperView over the plossl's by some 50%.
The magnification each offers is pretty much the same, the real difference is the AFOV. If you have a 2" focuser, I'd recommend the SuperView. The SuperView's are a very good EP for their price.
For comparison, the Plossl:
http://www.bintel.com.au/Eyepieces-a...oductview.aspx
The SuperView:
http://www.bintel.com.au/Eyepieces-a...oductview.aspx
Mental.