Most of our customers do not over line a fly rod by a full line size. We do sell fly lines that are 1/2 size heavier such as the GPX or Rio Grand to customers who want to slow down a rod a little. We sell quite a few of those. Over lining would help you load the rod at a shorter distance but I would not do it. I have tried it before and was not happy with the result.
I do have a GPX on a Winston LT and I like that combination.
I bought a TFO BVK 6 Weight last Summer and I really like it a lot. It is not over lined. I'm planning to buy a BVK 7 weight this year. They are really nice rods for the money. They are light too. If you do not want to spend the money on a Sage One, a Helios or a high end Winston, the BVK is a very good less expensive choice.