Here you go...
Bazzill - Fairly easy to blend. Some bleeding through the back.
Canson - Markers bled but it was pretty easy to blend. Bled through the back onto the next piece of cardstock.
CC Designs - Really nice paper to blend on - took the ink very nice. Some bleeding through to the back.
Copic - Really nice paper to blend - some bleeding through the back.
Crafters Companion - Easy to color and farily easy to blend. Some line marks show as you can see from the Bic, Sharpie & Copic examples. Some bleeding through the back.
Georgia Pacific - Took ink well, fairly easy to blend. Little bleeding through the back.
HP Photo Paper - Glossy Side - Awful blending, shows every pen mark. No bleeding through the back though.
HP Photo Paper - Matte Side - No good for blending but it did take the ink nicely. Some bleeding on through to the back.
JudiKins MatteKote - A bit difficult to blend - Line marks very streaky. Did not bleed through to the back at all.
La Blanche - Somewhat difficult to blend but it did take the ink nicely. Very streaky as you can see from the extra marker tests. Each time I lifted the marker there was a little dot left where the marker stopped. Did not bleed through the back at all.
Neenah 80lb Cardstock - Great color & blending. Did soak through the back.
Neenah Index - Again, great color & blending and about the same bleeding as the Neenah 80lb Cardstock.
Ranger Stamping Paper - Fairly difficult to blend - everywhere you stopped the marker left a little dot of color. Extremely hard to get away from. (it shows up really well on the green marker examples) No bleeding through to the back.
Simon Says Stamp - EXCELLENT paper - took color well, blended easily and no bleeding what so ever. Really nice paper.
Strathmore - Took color well, fairly easy to blend and little to no bleeding through to the back.
I hope these comparisons are helpful...
tomorrow I'll be back with a few final tests to share.