MijoShop is an excellent product and I have it installed with all the Stackideas products as part of a community driven website around EasySocial.
I know JReviews is a great product too and was about to get it when I thought I would check if it was complementary to MijoShop or a duplication as both handle product reviews.
I believe there may be a slight overlap in product reviews but JReviews offers more and the integration with EasySocial is obviously a major plus, all advice/opinions welcome.