For those who didn't already read it, you must change the memory allocated to your launcher to 1.5-2.0GB (the default is 1.0GB) or you will experience lag, especially in built up areas (like SpawnWorld & GameWorld). This is because Forge 1.7.10 is much more resource intensive than 1.6.4 (virtually every official Technic modpack also recommends this now).
It's easy to do but if you're not sure you can also find a brief guide on that page too.
One other thing that I've mentioned and that a lot of people don't realise is that more memory does not always give better performance, setting it higher than 2.0GB can actually cause as much lag as having it set too low because of how Java manages the assigned memory. So if you've assigned more than 2.0GB and are experiencing client lag (low FPS) try lowering it and you might be surprised!
