I don't believe the SFRA has had any effect on the pace of flight training at these airports, compared to the rest of the country. The rental outfits and clubs at Manassas, Leesburg, Gaithersburg, Freeway, and Fort Meade seem to stay busy. Schools at outlying airports, Culpeper comes to mind, sometimes advertise that their pilots don't have to deal with it, but the metro area is where the customers are, so there.

Manassas is the only towered GA airport in the SFRA; even on its best day I don't think it gets that busy.

The process has had no real streamlining, other than that the SFRA (it used to be an ADIZ) shrank significantly a little over two (or three?) years ago and the Leesburg manuevering area was established. Over time, the pilots and ATC have settled into their roles and responsibilities; things go smoothly over 99% of the time.

For new students at these airports, filing the SFRA flight plans and talking to ATC in and out just seems like a normal part of life. For those of us a bit longer in the tooth, it's a tolerable pain in the a$$.