I've never tried it.
I have the Delmhorst Navigator Pro and I really like it. It's very simple to use. I have had a couple guys who have used both say that they were both good meters but they felt the Delmhorst was better and easier to use. That feedback was what was ultimatley influenced my buying decision.
That's funny Richard. I own two of the mms plus for a similiar reason as Richard. We got one at a pawn shop for almost nothing because it did not work. The other one we bought. We like them and have had them for years.