ISA Server without the "A"

I have been experimenting with my ISA2006 server for my corporate domain and have come to the conclusion that the ISA server seems more responsive running as an "IS" server.....this may confuse many people, but here comes the explanation:
ISA Server is Internet Security and Acceleration server, here is a breakdown of what all the words do:
1. Internet - Allows users to access the Internet via a proxy server intergrated into ISA2K6.
2. Security - Allows granular application of polices to allow or deny users access and includes attack protection.
3. Acceleration - Enabled caching of website which enables you to load a local copy of the site which is quicker.
It is this last step, the Acceleration setup that I have disabled as it causes more issues if you need "up to date" copys of websites also I find the cache relatively inconsistent when trying to quickly load cached are some stats....
Protocl Definition
Protocol to ISA : http
Traffic Requests to ISA: 8398251
% of Traffic to ISA : 55%
Cache Definition
Objects returned from the Internet: 62.20%
Objects returned from cache without verification: 27.70%
Objects returned from cache after verifying that they have not changed: 7.60%
Objects returned from the Internet, updating a file in cache: 2.50%
So, here with the Cache on 62.20% of traffic was obtained from the internet bypassing the cache and a small percentage of 7.6% of pages were confirmed and verified from the cache.
Therefore in my opinion the "Cache" module to ISA slows the internet service down rather than speed it up.....therefore if you have an ISA server in your enterprise turn off the cache!