I run all my tires at the same pressure.
I have been thinking about doing that myself, and recently been running a little higher than the spec in the front. The factory front/rear split might just be for legal reasons- to make the car understeer for people that can't control oversteer, and seems to make the tires wear too fast on the edges.
I am not sure I believe the 5.XCFM claim of the pump. that is twice my pump delivery. If it is true, I'll buy one for the time savings.
This pump will definitely deliver about twice the air of your pump, it's just that neither pump will deliver that actual CFM when there is backpressure, because that is the rating without it. This pump is twice as big and twice as heavy as yours, so it would be shocking if it didn't pump faster.
Before this pump I was using a Slime 40063 digital auto shutoff pump, which is pretty much the biggest pump that can use a regular 12v lighter receptacle. It was a 1.23 CFM pump, but the main issue was the duty cycle- it said to cool 25 minutes for every 10 minutes of runtime, and it took almost 10 minutes per a tire, so technically one needed to wait an hour and a quarter to air up 4 tires. I kept it in the shade and put a fan on it, and it worked, but made me nervous. The MESA pump can air up a tire in something like 2 minutes each and has a 30 minute runtime before cool down, so no duty cycle issues unless you are airing up a huge fleet.
I'm usually camping offroad for a full week with three people and a dog, so with all of my recovery gear, tools, and camping gear I'm usually just clean out of space... so not thrilled by the size of this pump. I carry a ton of recovery gear aboard including a hi-lift jack with sand base, lots of shackles, tree protectors, blocks, etc. Switching the roof tent over to an inflatable xped style mattress helped, as it now has room to store all of our pillows and sleeping bags up in the tent.