something that no one has mentioned as well is that acrylic doesn't transfer heat like glass does... so your tank temp should be more stable, if your heating/cooling is setup correctly.
also, having both glass and acrylic... just PLAN and leave it alone.
i know like, one of the fun things about this hobby is aquascaping. YES.
all the really nice acrylic tanks i've seen, the owners have aquascaped ahead of time on paper, at least a rough layout, and played with it and played with it, until they liked it.
i feel like reaquascaping regularly is very stressful to the inhabitants... obviously, as things grow, you have to make adjustments, but i think acrylic really lends itself to planning and leaving it alone.
if/when i ever get a big tank (6'x6') that's what i'm going to do. plan everything out. when you think about it, reaquascaping say a 75gallon, vs. a 400 gallon is totally different.
anyway, i'm rambling. but i know an acrylic fabricator who definitely confirms that the newer acrylic is much much better and stronger than the old ones. he's even mentioned to me that manufacturers are working on a totally scratch resistant coating for it. i love my glass 90, and i can't wait to see what my acrylic 20 looks like.