For me, the alcohol markers are easier to blend colors. I am not an artist by any means but I just don't think water based markers are meant to blend. The alcohol markers don't 'rough up'/make the paper pill.
I have some Copics, Bic fine point and just bought some Spectrum Noir. With any of them, practice, practice, practice. Each type of markers seems to have its 'quirk'. The alcohol markers bleed/soak into the paper and I think this helps them blend easier. The SN are my newest pens and I have to practice being a little less heavy handed because they seem to release more ink.
SN can be purchased with a coupon at JoAnn and Michael's. Don't have any other store near me that carry them.
Good luck on whatever markers you decide to purchase.