Mike,
I think the best way to gauge the performance of higher PSI pumps is to ask other members how long a life they are getting out of their pumps. I don't wish to stoke the debate, but I have seen the diffrence with a combination of higher flow rates with lower PSI and the performance has been outstanding! (100PSI Fully variable speed pump with PTFE/ Teflon open bore 3/8" solution hose). The problem with higher PSI is that the pump once it hits the flow rate you seek, then cycles on bypass and continues to cycle on bypass. This happens the majority of the time, as the pump is sending solution through a small bore hose into a 2002, 2003 jet/jets. The conversation I have had with pump manufacturers has led me to the fact that these pumps ARE NOT suitable for the situation thay are being used for. Also how much of the excess solution becomes airborne and causes atomisation in the surrounding atmosphere?
My advice would be to ask around and do some research before upgrading!