Allow users to leave reviews / recommendations

Hi all
Another question, this time on a possible review / recommendation process. I’d like users to be able to add their comments to s/o else’s profile by linking it to an existing transaction.

Let’s say I bought a bike from s/o and I loved it, so I’ll go find the profile and leave him a review (Text) and is possible a positive / negative type of rating (I thought about TRUE /FALSE for this). I think I need to create a separate collection for “Reviews” and “Transaction” and link them to the user profile. Also, I was thinking to add a form to leave reviews and then display it in a simple list form with an icon “good or bad experience” for each entry. After each submission I’d like the profile to be updated with a calculated number of good & bad reviews (possibly with magic formulas assuming I could count good and bad somehow).

Please let me know if I’m heading in the right direction.
Thank you in advance.

Yep, that all sounds like it makes sense!

How did you end up counting good and bad?