That is great, it does sound like you have some decent raw water. I don't run the maxcap system, but I do have a dual DI chamber setup(full size, not the small horizontal ones), my ro water comes out at between 4 and 2, then the DI cleans it up to zero. I just got my system(Spectrapure) in the spring, DI cartridges are still going strong, I was sure I'd still have to replace these at 3 month or so intervals. Oh, we have a water softener too, that helps extend membrane life along with weekly or after every use backflushing the membrane. Good luck, I hope it keeps up those numbers or lack of numbers, I guess. Have a good one.
Matt