Split is a very touristy city, but still worth visiting; but a warning would have been nice. Split is a hub for cruise ships and bus travel so during the day it is filled with people from cruise ships and people staying in town. I think if we were to visit again, we would visit more islands in the area via ferries during the day and enjoy the quieter evenings in Split. For this, the ferries work well as their prices were relatively inexpensive. Getting to one of the islands (Solta) was only about $6 USD for about an hour's ride.
The beaches near the Marjan were nice and not too crowded. There aren't really long stretches of beach but instead access to the water is broken up into different areas. It works out so you can choose the area you want to hang out in (more shade or deeper water or stretches of large rocks to sunbathe on). Note: The walk to this area takes about 20-30 minutes and there is not a lot of shade.
Like the rest of Croatia, getting an apartment (apartman) in Split was pretty common. They tend to cost less than a hotel room and we were able to rent a small studio apartment for about 50€ per night which seemed to be the going rate for a studio or one bedroom.