would this be a good idea?

hey guys

Would working with subdomains be a good idea? example would be lets say acne niche, say for product reviews you make a subdomain for the product review, like "Productreview.XXXX.com" rather then XXXX.com/productreview . which one would be better for ranking in google?

I think the best way to find that out, is to test it.

Use 2 domains, 2 products, and try to utilize the same techniques in both cases