I have not , personally, used 2,700 K Flouro's to veg with. But nevertheless, here's my $.02 worth!
The difference between using, either, 2,700 K or 6,500 K CFL's (or Flouro's) for the purpose of either Vegging or Flowering has not been well documented - as opposed to Metal Halide vs. High Pressure Sodium lights (when used in the "wrong" stage). But I suspect that the results would be similar - that is to say that either light does work in either stage, with some degree of effectiveness. And even better, when both spectrums are combined in an optimum ratio, the effectiveness is magnified. In other words, "Yeah! Go out and buy some 6,500 K (Daylight) CFL's to go along with your HPS. That way you should kick some serious bud!
By the way - G.E. (General Electric) Daylight CFL bulbs are 6,500 K.