A good regular is ideal, for many reasons.
If shes good theres no risk, and if she does all the things you want then its the perfect arrangement, by all means if you want another punt with another WG then its fine, but a good regular solves a lot of my needs, and speaking from experience they get to know the sex, you get extras, longer time, unrushed and flexible, you get an all round better service and the punt is better as you have less nerves.
But make her not too regular, and do have someone different every now n then