I bought this product at a local retailer BECAUSE it had a blank side. I very much prefer the ability to create the map I want along with a pre-made map.

I would disagree with xwingdragon's comment that the makers lack imagination and instead believe they are cultivating the GM's imagination. With a little imagination this map can be very versatile. For example, instead of a guard tower, you can place guards to patrol along the 5' walls or hide a secret staircase to your custom dungeon on the backside under the warden's desk.

I really like this. The prison is generic enough that you can use it again as another sort of building. It could be a prison but again the cells could be the dormitory of a monastery or a garrison.

I've never liked floor plans that are too detailed or specific that you can only use them once. I think the level of detail is balanced enough that you can get away with slapping this down quite a few times over a campaign without your players quietly thinking "Oh, we're here... again." (Although I would've ditched the carpeted throne room for something sparser.)

I also like reverse sides that are a big expanse of something free from detail. Here we have flagstones but perhaps grass to match the prison's environment would've been better.

The prison side is very good...but not excellent (see Dave the Barbarian's review for some thoughts).

Once again, the makers of these maps have tried the do-one-side-nicely-and-leave-the-other-side-blank.
I have researched this map, and for the time being, I have not purchased it. (Why spend hard earned money for a half-baked job?)

They could have done a DUNGEON on the back (the secret prison escape route...), or another prison...even a prison half in ruins, or caves, or even a house for some pixies...the makers seem to lack imagination.
Some maps are a double whammy of goodness on both sides!
Not this one....

One star loss for good but not great prison.
Two star loss for blank side (oh, how dreadfully dull).

This is another fine quality map but it will serve a very limited purpose. I don't care for 5' thick walls for a basic prison, no guard towers, no solitary, and too many windows. I can see using it once or twice, but the prison you can get in one of map packs is just as helpful. I would have liked it more if they would have added another type of prison on the back. Maybe a maximum and minimum security style? Either way, it is still a good addition to the collection, but will see much less use than the others.