First solo at only fifteen hours.

[Colonel]

Being "old school", solo at 10 hours is normal,
solo at 5 hours is early, and solo at 15 hours
is late.

The above varies with the environment, of
course.  If a lot of time is logged on the ground
taxiing and waiting for takeoff, and flying to
and from a distant practice area, it's going to
be higher.

Time to solo is one of the most truly useless
metrics I can think of.  All it indicates is your
previous experience (which is quickly absorbed
and in fact is often a problem) and the slope
of your learning curve, which unfortunately
can plateau at any time and frequently does.

[David MacRay]

I don't know what their instructor turn over is like. The day I flew there the airport was reasonably quiet. I believe there were 3 of us in the circuit when I came back and one was a cub, we stopped to watch it land behind us at my request. (As often happens I worded that poorly, we stopped on the ramp where we could see the cub behind us in the circuit, then on final, land on the runway also in view.)

They are inside a class C that extend 30 nm around a major world renown airport. I can't find the practice area on the chart but suspect it is pretty far away.

In my opinion the airspace surrounding their airport would be fairly intense for most people while trying to learn to juggle radios and keep an airplane flying.