I just returned from SWRFI and a nice long cross country (VGT-ELP-AUS).
Following the advice of the KVGT controllers, I used this method, with mixed results. We were told that filing IFR from KVGT was a BAD idea, since all IFR departures are given the North Town One departure which adds 100 nm to your trip.
My intended route of flight was KVGT - BLD - DRK - PSX - and then continued on to the east, ending with a fuel stop in El Paso.
So, I filed an IFR flight plan with DRK as the starting point and the rest of the route as planned. I put in the remarks section that I would pick up the clearance in the air.
Following the advice of locals, I simply departed VFR, headed WEST to get out from under the Las Vegas Class Bravo airspace, climbed to 9500’ and headed direct DRK. This took me right over Vegas and got me on my intended route very quickly.
Now the hitch — when I called Center and tried to pick up my clearance as I neared Drake, I got the dreaded “Call back in ten minutes.” Ten minutes later I got the same treatment. I even tried to at least get flight following and got “No VFR services available at this time.”
Luckily, it looked like I would have VMC most of the way to ELP, so I just blew it off and went Direct ELP at 15,500. Having figured out that LA Center wanted nothing to do with me, I waited until I was in Albuquerque ARTCC and got flight following from them. As I neared ELP, I picked up a local IFR to get me down through a scattered layer of clouds and some dense haze. They were landing the ILS 22 at ELP.
So, it all worked out great, but would have been a HUGE pain if it had not been VFR conditions for much of the route.
I think the next time I will try picking up the clearance while on the ground and getting a void time, as suggested on this thread.