PayPal is preferred -- just like my injector service.

You will feel a difference. I felt it in my tired 300D NA engine. Of course your car will not be a Porsche, but it's a noticable performance upgrade.

Some folks with the 240D (4 cylinder engine) claim they run their engines without it and / or feel no difference. This is NOT for the 240D crowd. Further, by analogy, I have done a lot of injectors for folks and out of 100 sets, there's always 1 person who claims he felt really little to no difference. Of course the injectors before the R&R peed like crazy, weeped, and barely pushed any atomized fuel and with new nozzles no difference? So, the point I am trying to make is that yes, you will notice it and if you don't, then there's something else up with your engine. Hope the above, long winded response helped.