Yes, it is hard to keep the non-skid surface of a tub clean. I have a Kohler cast iron tub with a non-skid bottom and have to order an expensive cleaner online to clean it. Nothing else works on it.

Kohler cast iron would be my choice. Great looking, inexpensive.

You can't beat a good cast iron tub. They last forever and keep the water hot.

Do NOT buy one with a non-skid bottom! As one gets older or heavier, the only way to get out of a tub is to roll to ones side and then onto ones knees and then get up, one foot at a time. Ones knees will be torn to pieces by that non-skid finish. Sliding is essential. Same is true for pregnant women.

I recently visited a showroom so I could compare when trying to select our own tub. The (high end) acrylic and solid surface tubs were nearly the same to me (we didn't consider cast iron though). I was afraid the acrylic would sound like cheap plastic too, but was pleasently surprised. Ultimately we went with the solid surface as I learned acrylic surface isn't quite as durable and can show scratches easier and we preferred the design of a tub that was only available as a solid surface. But when looking to trim the budget, we were okay with the possibility of an acrylic to save.

Can you visit a showroom with both types so you can see for yourself?

I renovated the bathroom in my condo last year, which included replacing the tub. The enamel on the old tub (installed in the 1970s) was very scratched. The new one is a a Bootz porcelain on steel tub. It's only been about 15 months since the renovation was completed but I have no problems so far. The non-slip bottom is not difficult to keep clean. I use Barkeeper's Friend cleaner (easily available in stores and not expensive) per the manufacturer's instructions. I went with porcelain on steel because I live on the second floor of an apartment building, and since the old one was not cast iron I didn't know if the weight of a new cast iron tub would be a problem. I went with Bootz on the recommendation of my contractor, who has installed a bunch of them with no complaints.

A neighbor refinished their tub a few years back and the fumes were terrible.

Hi! If the OP is still checking this, I'd love to hear what you decided and how things turned out. I'm in precisely the same spot (and space restricted with a 30 x 60 tub space - don't want to take out the tub unless I can get something deeper).

What did you all pick?

I ended up keeping my old tub and only sometimes regret it (when I want a soak). I was too concerned for the costs / what might be behind the walls and couldn't find a tub that was sufficiently deep (but as narrow as I needed) to make it worthwhile. I retiled instead and have been very happy with the results and with the cost.