To some extend it is possible to adjust the bsp engine for outdoor or indoor worlds.
For outdoor worlds you can fx. scale the texture up by 3. That will also affect the subdivide value. Since its on a 2 dimensional plan it reduce the w_poly 9 times. You just have to remember to adjust the maxnodesize too
For indoor rooms you want more quality. There you just scale the tex to 0.5. That results in sharper texture and nicer lighting on the expense of w_poly.