Flying and working in both V4 and V3.4.
Also FSX SE and FSX installed for checking all projects for continuity.
P3D v4
Absolutely sold on V4.
Primarily for flying and video work, but even more as a learning tool. Lots and lots to add to the skill sets, and this will take literally years. No time like the present to begin the process. At present, projects will need to be approached separately due to the proprietary nature of the 64bit platform.
P3D v3.4
For development and testing of 32 bit projects. Also doing scenery placements with tools that still favor 32 bit i.e Instant Scenery, SBuilderX, MCX etc.
FSX SE and FSX
For development and testing of those 32 bit projects intended for FSX users.
Something to consider is that developers are burning the candle at multiple ends to cover the spread. This is an accepted cost of doing business for those staying in the game, but end users will need to accept the fact that those costs will need to be passed on. With the jump to 64 bit, products intended only for that platform should actually be more predictable due to the fact that the development curve for the actual simulator has reached a plateau. Logically, product development should require less re-engineering to adjust for simulator updates.