Well here is my 2cc's on increasing test dosages...
As a rule I wouldn't increase any dosages while you are still making gains as it really is un-necessary both health wise and financially. I always advocate swtiching up other areas of your training or nutrition before increasing dosages of " supplements".
Now I had a post over on muscle mayhem a few months back about this very subject and in a nutshell what i posted was that your body if subjected to large amounts of testosterone or any steroid for that matter for exteneded peroids of time , meaning 32 weeks or longer is eventually going to create a new set point in which your body call's it's normal level. The reason being is that your body has an internal record of what dosages you have taken etc. By increasing the doasges from say 1000mgs to 1500mgs per week, in all likelyhood you will probably grow a bit more, ( probably most of it would come from increased water weight) , but their wouldn't be any real outstanding bebfits. ( Remember your ledig cells only secrete 9-11 mgs of natural test per day, so taking 1000mgs per week is 100x what your body produces naturally.) however it has been my experience that after coming off a cycle of 1500 mgs per week and then going back on later you body needs at least 1500mgs per week to return to the state of which it was at before the last cycle ended.
Now there are exceptions to everything and if you took an extended peroid of time off and your recpetors had time to clean house then 1000mgs per week again would in all likelyhood allow you to gain.
For most people the side effects more than outweigh the bebefits at 2g per week of test. Some people do take that much but is it really necessary unless you plan to stand on stage, and at that more can be done with less.
In my opinion you can gain just as well on 1200 - 1500 mgs as you can with 2,000. If for some reason you couldn't grow on an extra 500mgs of test per week then maybe it is time to look at other avenues.
Hope this helps
Maverick