The only problem I see with FPSC is the limitations it poses. X10 fixed a lot of these issues, but even games like GTA IV can run on XP without issue. Anyway, the limitations are:
1. Ragdoll physics. In a modern FPS, they are a must. The migration might offer this, but even then it will still be rather glitchy.
2. Textures. Even though you set the settings very high, textures still look like garbage nearly all the time.
3. Lack of decent shaders. CoZ's shaders are good, but we need more variety.
4. The "falling through floor" bug still has YET to be fixed. How many versions now has it not worked? Honestly.
5. Dodgy movement / collision detection.
6. Weapons. Most weapons from the weapon packs are below average on other FPS games. On packs 9 and 10, you can continuously reload the gun even when the clip is full. An issue that should have been tested.
7. You still don't feel like you're playing a FPS. The enemies have horrible AI, there is no cover system, there is nothing that would make you feel like you're in an intense battle.
8. Anything decent has to be scripted in. If they really wanted to make it easy, they would include allies, they would include event checkpoints, etc.
9. Realistic physics. Boxes falling down steps is decent, but it's nothing we haven't seen on old games such as Half-Life. Dynamic windows need to be made, meaning ones that actually shatter if ran into them with a gun, etc.
10. Most animations look choppy and poorly produced. Mainly this applies to the enemies dying. They don't fall like one would expect, they kinda just dive for the ground.
11. Most of the time objects look correctly placed in the editor, but then you play the game and realize that everything is 50,000 meters apart.
12. There are no dynamic environments. No matter how many packs are made for this, you can't dynamically mold and shape environments. Everything is flat. It always will be.
Well, I think you get my point. Basically I'm saying it's a decent editor but needs major work to meet today's standards.
Temporarly away from the Phoenix Sentry.