We have about 5 in our local fleet. Putting aside the cost and value issues since those are subjective, it is a good boat. Fragile? It's not a "Blue Water" boat by any means but as MS pointed out it is TPI built and not in any way weak.
We have very good competition among the "One design" Alerions, especially for those sailors who are of the vintage where smart sailing wins over edge of control sailing. In other words, for the fifty and above set, the physical demands are light.
I've seen a couple sailing the boat in 25 kts., while I'd doused the sails in my 356. They were having a great time - in foulies. It can be a wet boat.
As for accomodations, there isn't a bunk I could sleep on.
If you want a daysailor that is physically undemanding, and can sail easily in a wide variety of conditions, is easy to single or double hand, and is easy on the eyes, has a diesel engine, it should be considered.
A good value? That's up to the buyer. I think they hold up pretty well on the used market but you would need to consult a broker for that info.