i researched tubs recently for what seemed like forever! maax acrylic tubs and americast were in the mix.
if you've got the extra cash to input, you might choose americast over acrylic for the heat-retention properties.
i chose the deepest maax 5' acrylic soaking tub i could afford on my budget (under $600) and couldn't have come near the price if i'd gone with the same features in americast.
frankly, i like the finish feel and easy care and durability of americast, but it's a step beyond what i prefer to spend right now.
maax makes a good acrylic tub from what i understand talking with various tub owners and plumbline - so if you go with acrylic, check out maax in your tub search. maax's builder's line of tubs is pretty economical.
oh - they have great installation specs, too, for what that's worth!
enjoy , kavita