I share your joy of flying the Boeing 737 NG. I will purchase the IFLY model based on it's outstanding reviews. I would also like to compare it to the current release of Ariane's Boeing 737NG plane list.
http://www.arianedesign.com/ They are just as advanced as PMDG and don't get the press it deserves as does the IFLY variant. I think all three models should be compared equally, but the cost of owning all three might be a downfall. I can't imagine anyone who would not want to own at least one of these. Compare and comment once you can. We all look forward to PMDG's release of course. I own, and have paid for, everything they have released. They, as a company, are the industry standard.