At the flight school I teach at, we have two different blocks; MWF and TR
. There is actually a marked difference in the quality and information retention of students between those that fly 2 days each week and three days each week.
Within reason, I would fly as much as you can, and for several reasons.
First is recency of experience. You tend to learn more new stuff if you don't have to re-learn old stuff first. By putting even a week between flights, you run a very high risk of forgetting even simple things from last time. Even with almost 700 hours, if I go over a week or two without flying, it really shows.
Second, it'll take you a lot less time overall to complete your certificate, and this actually has a lot to do with the first reason. The time it takes to complete the license goes up exponentially in instead of being linear. When you take time off, you end up spending more hours flight time learning the material, and when you aren't flying as much, this ends up costing a lot of calendar time also.
Expanding on the second is the third: cost. When you fly lots, the money will go quick, but in the long run it will cost less.
It all goes back to recency of experience...the more frequent you fly, the better!