optically they are pretty close, the distortion issue is going to be much more related to the individual casting, rather than the differences between glas and plastic... if the acrylic has casting distortions then yea, and thats more likely than it is with glass. but i would also think that if there were that big of a defect that they wouldnt sell it...
as for maint. i think that glass is easier, cause you can use a real metal scraper to clean the inside, and just about anything on the outside(if your careful not to get any in the tank)
With the acrylic, if you ever wanted to silicone anything, well, your screwed, cause it wont stick very well, and if you scratch it, it can be repaired, but thats lots and lots of work, and may leave distortions... not to metnion that you cant just clean it with anything, no metal scrapers, and no abrasive scrubbies, so that makes cleaning the inside a little more challenging.. and you have to be careful about what chemicals you use on it as well, some cause crazing, some cause other problems...
then theres the part where this tank is a "tall" meaning that my standard 75 is 48 wide, 18 front to back and about 20 tall(thats going from memory) and this one is taller and less distance front to back.. I prefer more surface area....
not to mention that its a 75, but i'd bet you loose some of that due to all the plumbing being in that back section... so your limiting and short changing yourself on tank volume...
personally, i dont like it, its an interesting concept, but not something i would spend 700 bucks on, i could set up a nicer, bigger tank for that kinda $$ or at least if your willing to give the the $$ i'm willing to try...
not to mention that i never buy anything "ready to go", theres allways something i wanna change, so, i figure why get stuck with someone else's ideas, when i can just build what i think is right...
but if you get it, let us know what you think.. i'm currious now...