What are the top 5 attributes of an acrylic bathtub that you look for to show you that it is a quality product?

Bathtub size and style matters because it needs to fit you in it, and you need to enjoy how it looks.
Check where the drain is positioned in the tub, you don't want to have to re-model anything just to compensate for bad drain positioning in the tub.
Last but definitely not least I would have to say budget!

Sorry I couldn't come up with the top five but I hope these are helpful.

I am no fan of plastic or fiberglass bathtubs but the first thing I look for in a acrylic tub is to check and see if the manufacture went "the extra mile" and built in supports for the floor of the tub. If a plumber installs a plastic tub without first "bedding" it.( ie; puddling cement or mortar under the tub for support ) I can guarantee that in time one of two things will happen.
1. The drain seal will rupture **OR**
2. The tub will develop cracks in the floor of the tub.
Outside of that Plastic are the easiest to install since you can pick one up and set it easily. Installed correctly they look great and properly bedded will give you years of trouble free service.
Why do you want to know 5 reasons. Are you thinking of installing one? Regards. Tom

Acrylic tubs are not what they used to be - even if you go few years back, it will make a huge difference in quality. They used to be called "plastic tubs". Now, almost all of them have Gel Coating that makes it scratch resistant and prevents discoloration. Besides the ease of installation one of the biggest advantages of having acrylic shell tub is that water won't lose heat as rapidly as with Cast Iron tub. Additionally, you have better selection of models, types, brands and features than with Cast Iron tubs. As far as cost goes, acrylic tubs are about 50% less expensive than its Cast Iron counterparts. If you are considering whirlpool tub than surprisingly, Lowe's carries good quality Jacuzzi brand whirlpool tubs for very good (low) prices. Hope that helps. Milo

Thanks Milo for the update. Yeah! Times change andI haven't. It's been over 20 years since I set a tub. I learn a lot from you guys. Cheers, Tom