The maxcap 90 is a great unit. I'm going to be setting one up for my friend tomorrow night. It comes with a lot of nice features like the dual tds meters and dual DI cartridges. If you have the extra spending money, then it is a great way to go. Otherwise the Typhoon will fit all your needs.
Regarding multiple prefilters. You need to know about your tap water conditions. If you have chloramines then the dual carbon filters on the Typhoon will provide longer contact time and this is a good thing. With the maxcap you only have one so I would be VERY meticulous about replacing it every 6 months if you have chloramines. You can also ask spectrapure how they feel about the issue of chloramines. Otherwise, it won't matter much. Also regarding the size of the micron ratings on the prefilters. Once you buy one of these units, you are pretty much free to use sediment filters and carbon filters from any reputable source. If you want to try a 1 micron sediment filter and finer carbon filter, then try it and simply watch your pressure gauge to make sure they don't clog prematurely (as would happen with high sediment tap water). The only unit I wouldn't try this on is the maxcap because it only uses the one carbon filter. My guess is they have choosen something special so that they can get by with only that one carbon block and still take care of most peoples needs. However, I would clarify with them before purchase. AZdesertRat is kindof a spectrapure expert. Maybe he can chime in.
sorry for rambling,
FB