interesting. Why are you sick of acrylic?
In a nutshell, acrylic is just too soft.
To expand further on that, it scratches easy
To go even further, if you need to do any serious cleaning on the surfaces (inside) you will be in for a world of hurt.
Yes acrylic "invisible" compared to glass... assuming the acrylic is perfectly clean and I mean PERFECTLY. My biggest problem is coraline algae, I don't know what it is, but every tank I've had whether it was glass or acrylic could not grow the stuff ... on rocks ... however it grew like crazy over every flat surface inside the tank. And removing coraline from acrylic is the WORST, sure you can take care of small little dots here and there with a credit card, and Mighty Magnet even sells a product (maybe repackaged) that is pretty damn great for removing it... but if I let it go for more than a week (which isn't too hard if I get really busy or go away on vacation) large colonies start to form, and it goes from a pain to remove to "WHY ME!!!!!"
With my old glass tank if that happened I pull out a razor blade and go to town scrape everything away in a few minutes and viola! Looks clear as can be... and yes it looks clearer than acrylic. Sure acrylic (and to a lesser extend starphire) is clearer, but only if it has no stuff on it, if it does however then your eye instantly focuses on it and you can see the entire glass/acrylic pane no problem.
So even though the tank I'm fixing up 8' x 3' is acrylic, I got it because it was a cheap used one (and I mean cheap!) and the place that made it does get good praise, so it's good enough. But if I ever had to get a new tank, doesn't matter if it's 12' x 8' tank that's free, if it's acrylic I don't want it! (ok if it's FREE maybe..)