I spent all last winter vLiting Win7 to see if it could run faster on old boxes with 528 ram and low CPU.
What I found is that there is no appreciable difference in bare bones Vliting than Basic or Ultimate. Low ram or video shuts down aero by default so that is handled. Then the services which are normally shutable - security center, defender, firewall, updates, etc - simply do not yield back enough performance gains to do without them. They are infinitely more optimized in Win7 than Vista.
The only way I made appreciable gains at recovering RAM is to cut down my gadgets and strip my AV down to Avast, run with Defender and Win Firewall.
This was hard to swallow, but it represented dozens of vLite attempts and successes, and every possible service config: Vlite to the bones, Basic, Starter - the only need is to get it on a netbook. Ultimate will default as low as any other when on 528 ram, low CPU.