I think the PE coverage is just perfect in size. And I find the area of choice very interesting.
This is my story, and the reasons behind the above statements:
I'm currently working on my Private Pilot License. I have been a flight simulation enthusiast for most of my life, so doing all kinds of practice in the simulator instantly became a natural part of my real-world flight training.
Up until spring this year, I had not heard of PE, just VATSIM. Before knowing about PE, I had connected to VATSIM several times, but there were never any controllers online, so I found it boring. (I live in Northern Europe, more specifically Sweden, and the population is rather sparse here, so I guess that explains it. I wanted to fly in my own area, of course.) Then one day early summer this year I read about PE (can't remember where) and signed up for the trial period. That was the beginning of something amazing.
But it took a while before I had the confident to make my first call on the radio...
To begin with, I had to study the VFR maps (I only fly VFR, and will probably stay doing so all the time). They differ a lot from the ones that we have here in Sweden. The US maps are much more busy, so it took a while just to get a basic grip on them (the tutorial videos linked from this site were/are especially helpful). Then we have the airspace classes. In Sweden we only have C and G, so I had to study B, D and E too. And finally, the radio phraseology. Sure, it is supposed to be a world-wide standardized aviation language, but still, there are some minor discrepancies that I had to find out.
I started out doing some flights around non-towered airports, making calls on the CTAF frequency. Nobody shouted at me or sent me a angry e-mails, so I guess I succeeded in staying out of the controlled airspace!

Next step was to take-off from a class D airport. I did that, but wow, was I nervous!

I did a couple of those flights, i.e. taking-off from class D for a non-towered airport landing. It went fine. My next step was to fly
into a class D airport and land. It went well too, and was a lot of fun! This is how far I have got at this point. My next step is to try flight following, and later also enter class C (just need to refresh those airspace rules a bit first).
With the current coverage of PE, I see that I can keep flying for almost an indefinitely period of time. Not just the fact that there are so many combinations of airports (as Keith mentions in a previous post), but also because of the airspace design, and the way it looks. For example, last night I scanned through the VFR maps looking for an interesting VFR opportunity -- I found one rather quick: Taking off from Perris Valley (L65), making a quick turn to the Northeast to avoid the class C airspace ranging from surface and up, then stay below another C sector with its floor at 2900 ft, staying on the East side of a small mountain, get out of the class C sector above by rounding a small lake, go up North and climb thousand feet or so to avoid crashing into another mountain, call the San Bernardino (SBD; class D) tower for landing, and finally land there. All this in 10-15 intense minutes. Not a single moment of resting or enjoying the view! Just constant checking of location, maps, heading, altitude, radio, clearances, speed etc. What a thrill!

For me, I find the pre-flight planning a great pleasure too. I have paper maps, so I draw the true tracks on those, then calculate compass headings based on wind, deviation and variation. It is a lot of fun scanning for those interesting and challenging flights in the maps -- I believe there are, more or less, an unlimited number of those in the PE coverage area.
And when the planning is done and I'm ready to fly, I can connect to PE knowing that there is a controller online. That is worth every penny. And the controllers are extremely professional (although I haven't got that many real-world hours of radio talk to compare with, yet).
I just realized the other day that flying (in my flight simulator) without the online service that PE provides, is becoming less and less fun. No one to talk to. No one cares if you violate controlled airspaces. No radio chatter. Nothing.
I find PE cheap for the quality service it offers. (I have the hourly plan now, but will soon switch to the monthly.) Okay, I admit, I would probably not be ready for a 5-6 times price increase, but today's pricing is definitely very much beneficial for the customers.
I really wish and hope that more people find PE, so that the customer base increases. Not because I want more simultaneous traffic (I personally don't care about that), but because I want PE to be financially secured so that it can stay around for many years to come. I'll do my best to promote the service to my fellow aviation friends at my local aero club. It is indeed a great training tool, even for us on the other side of the Atlantic Ocean.
Have a nice day!
