Once I got re-acquainted with the Gamma Hi-Tech grip after using leather for years, I will never use anything else. The Gamma grip is absolutely perfect and doesn't need an overgrip.
If you're looking for a synthetic that LASTS and has good comfort, try the Hi-tech. For me, I had to change overgrips on my leather every week or two. Now I've been using the Gamma grip without an overgrip for more than a month and it looks hardly used at all. I'll probably end up getting 6 months out of this grip for a measly $5. Compare that to switching overgrips every week for $1.50 and it really adds up to a significant savings.
Besides the cost savings, it's really a great performing tacky grip.
Lois: "Peter, I'm not wearing any panties."
Peter: "That's ok, honey. We can throw that chair out."