i always try to remain impartial mate, that's why i haven't been round pimping my 2405FPW. It happens to be the screen most suited to my needs, but then i pretty much never game so i know it might not suit everyone. Regarding the 2405FPW vs Acer 2416W i think it will be a similar case to the discussion above about the 3ms Viewsonic VX2022W. While Samsung have rated the panel as faster than the one used in the 2405FPW, chances are it's only a slight tweaking of the overdrive control, and a high exageration of the spec on paper. Samsung list the panel used in the 2405FPW as 12ms, while Dell are much more conservative (and realistic) at 16ms. This is after their own testing, Dell are one of the few companies who do this really.
The Acer 2416W may be a litte faster on paper, and perhaps there may be a slight improvement in real responsiveness. However, Samsung have had issues in the past with overdrive application, and while they have lowered the response time on paper and in advanced testing, this doesn't really translate into any real performance improvement when it comes down to real use. The 193P+ is an example of this, being an 8ms rated panel, while not offering any real improvement in use to the 20ms rated 193P (same panel essentially).
There might hopefully be a little improvement, and let's hope it's not at the cost of DVD playback, as poorly controlled overdrive can lead to some nasty accentuation of noise in the movie playback (like on their Samsung 930BF for example). If there is actually any change, it may be a little more responsive (let's hope they manage this) and if all goes well with the control of the overdrive (again, let's hope) then this shouldnt have any draw backs. The design will obviously be different, and Acer haven't been known for making particularly high quality monitors in the past. Maybe some other manufacturers will adopt the same panel, and im sure they will (prob in the new Dell 2405FPW update i would imagine too). Anyway, all speculative for now, but that is my take on it