There is nothing wrong with running the occasional special deal.
I'd probably not automatically tie it to reviews-- simply because its very difficult to enforce it and force the review. Honestly, calling it a "review special" will also occasionally put a target on your back from a certain subset of guys (no-- not any of the guys on this thread-- PM me if you want more information-- I see a lot backchannel).
Do what works best for your business. Just be careful and be safe out there!