You can't compare PMDG 737NG for FS9 with iFly's. PMDG 737NG was way released before (back in 2003 i think). PMDG 737NG was a milestone in FS addon history back then, but the bar has been raised numerous times, especially after their 747-400 QOTS and MD-11 release, which IMO has one of the most complex system simulations out there. Thus the iFly, benefiting from the developments, is quite superior to the original PMDG 737NG in many aspects. For example, it has working IRS simulation.Clearly iFly is the best 737NG out there for FS9 and great value too. For US$55 (at Flight1) you got every 737NG out there (including 3 BBJ models) except 737-700ER and 737-900ER (which IIRC, will be added in future SP to the owners soon enough for free). Well that's fantastic, isn't it? Besides, their models and variants (MCP new/old style, eyebrows, winglets, displays) are quite abundant. This is one of the best FS9 payware products IMO. From what I heard, Arianne's 737NG says that iFly's 737NG is good as well and quite as complex, and more importantly, far less expensive.In addition, you got nice team of people answering and catering to your rants and some of your demands on their support forums.