I owned a 2520 straight inboard. It’s a great boat. The engine box is not a hindrance, it makes great seating and an excellent work / fishing platform. You also have full transom access, a full-length swim platform, and a great space to put the name and hail!
The problem I had with mine was the previous owner re-powered it with too small an engine. It was a Chev. 350 but only 250-270 hp. You need at least 350 horses to move that boat.
The beauty thing with an inboard is when you need to re-power, you can get a re-manned short block for $5-$6000. with a 2-yr warranty. Replacing a 350 HP outboard costs waayy more than that. Other than risers and manifolds every few years, it was pretty low maintenance. You can buy filters, belts, ign. parts, etc. at an auto parts store, rather than buying over-priced genuine outboard parts. Also, there are loads of good-quality after-market engine components (risers, manifolds, cooling system parts) available for a fraction of Mercruiser brand prices. If you got the horses and a good set of trim tabs it’s a great boat.