Legacy applications already on VFP are a good candidate. If you plan to move to iOS and Android apps, VFP is not for you. Also, in future access to VFP programmers may be limited. You could use VFP as a powerful database tool. I know of many programmers who love to exploit the features of VFP to create easy to use applications.
Over the course of months/years, various security exploits and other issues are discovered and patched in AIR, often requiring you to rebuild and resubmit mobile apps to the various storefronts. This happens often enough that it's worth mentioning as a major con.
While development on Adobe AIR seems to be fairly constant, there is very little communication between the community and Adobe regarding the future and general support of AIR. The track record of Flash (and particularly Flash Mobile) does not inspire much confidence that Adobe intends to support Flash/AIR for years to come.
Adobe AIR does not seem to perform as well (in terms of raw performance, memory usage, framerates, responsiveness, etc.) as other hybrid solutions for certain tasks. For example using shaders tends to be experimental still, and graphic/animation intensive projects often require the use of third party frameworks such as Starling.
Although Adobe AIR is just an SDK without an actual "UI" it's commonly used within Flash, Flash Builder, or FlashDevelop. Considering the integration with Flash IDE, there are very few tools that can compete with its features.
Although MS has discontinued support of VFP there is a good community of programmers that are available for help. In fact we have several programmers at Apptread that are skilled not only in VFP but also .NET so that if there is a need to migrate some parts of applications to .NET , it is easy for us to do that.
Originally, Adobe AIR was the only game in town, and its blend of flexibility in platforms it could publish to (PC, Mac, iOS, Android), ease of use, and familiarity made it the clear choice. Now Adobe no longer supports it, and we’ve found the transition to Harmon unworkable for us.
We are only using FoxPro because it is the only way to add custom plugins into the software we use to manage our stock. FoxPro is a semi-oriented object language and should clearly not be compared with recent technologies.
