If you can find a 152 Aerobat...not a 150 because the 152 has a little more hp...you will have a blast. I have probably over a thousand hours as a CFI, specifically in the 152. I taught in all the usual stuff, but the 152 was the primary bread and butter airplane. Yeah the doors are flimsy and the feeling of not having a whole lot under you is different (especially if you are used to the 172, Pipers or a Cirrus which will really spoil you.) Give it a chance though. It is extremely manuverable, and more forgiving in a loss of power scenario than a Piper. I know the little Lycoming engine seems like a lawn mower, but those things are tough as nails. I never had any major issues in all my time in them. Maybe a fouled plug or a bad mag. We had some pretty tired looking 152s on the outside...as in paint, interior, avionics, but the engines were constantly inspected, repaired and overhauled when needed. I would think any school in compliance with FAA regs would be the same. The paint and cloth don't mean anything to me. I've ridden in aesthetically beautiful, mechanically horrifying airplanes quite a few times.
The biggest event we ever had with our 152s was when one took off headed across the bay and threw a rod. Oil blew all over thhe windshield, but darn if that engine didn't keep chugging on 3 jugs all the way across the water ( a good 6 miles or so) until finally it ran out of oil. It made it and landed just offshore. Everyone was fine.
As a CFI I found people were sometimes intimidated by the larger, heavier 172 and while skeptical about the 152's flimsiness in comparison, they seemed to gain confidence in controlling the aircraft faster in the 152. Landings came easier, and generally people soloed a few hours earlier, as least from what I saw.
Like I said before...if you can find an Aerobat 152 and someone who can instruct you in it....you'll love it. It doesn't have the horsepower of the fancy aerobatic airplanes, so you learn about maximizing potential energy with just enough juice to make it fun.