I highly recommend the Pentax Digital Spotmeter. It's easy to use, has no "on" switch and works really well in the field. I've tried the Sekonic 758 and don't find it very usable in the field just because I'd have to keep turning it on and it didn't fit in my pocket as well.
I actually tried getting the Sekonic, couldn't stand it, returned it, bought the Pentax off of eBay, liked that, then bought the Sekonic again a year later to use for flash work. Now I have both, but almost never use the spot part of the Sekonic.