Not really sure I would call mine a big tank..... 90 gal, or a canopy really, as its really more of a built in. But I have pneumatic struts on my face panel that holds it up, and mostly out of the way. My suggestion would be to really think about how you access the top of your tank, and how you will get to the things you need to get to. Daily feeding is a big enough pain with any type of canopy, now add the complication of cleaning it. Will you scrape your back panel? Not if you cant get too it, or it isn't tall enough to at least crawl into it. If its completely removable, you can eliminate most of the servicing problems, but if it is a big canopy, make sure you can get it out of the way by yourself (no one is going to be there when something goes wrong and your forced to scuba).
I like mine just fine, might even do it again if I had to, but there's always something you would change once you've had to actually live with it. And when you make that change, you might just find something else that's affected, and wished you just went with no canopy and a frag flat
Here are a couple old pics, it's hard to see any detail in an all black wall unit, but you get the idea.