I have the same problems. Minecraft needs about 40 seconds to load and then I can barely move Steve or even look around - 5FPS max.
I already tried changing the allocated RAM - from 1GB to 6GB - no difference what so ever.
In the debug screen of MC it shows that MC is allocating only 35% of what it could.
The technic launcher is recognizing the right java installation.
My specs:
Intel Core i7-2670QM 2.2GHz
NVIDIA GeForce GT 555M Cuda 2GB
16GB DDR3 RAM
Windows 7 64-bit
Java Version 7 64-bit
I checked point 3) of Roversword's post. I have no such variable.
Hope anyone knows what's causing this, since there are a lot of people out there who have this problem - and then there are those who haven't :-)
Thanks in advance.