I've used both briefly in ARES functions, I'm more familiar with Yaesu and Icoms, so when using the Kenwood, there was the detriment of not having learned how their menus think and what their abbreviations mean. That's about the extent of my bias on the matter.
The big difference, is the Kenwoods can digipeat and the Yaesu will not. And when you're trying to get some weak handheld signals to an igate from remote areas, that can be a very big deal.
The Kenwood also plays a little nicer when working with the AvMAP Geosats being able to display all the APRS icons if you're looking to go that route (I'm not 100% sure on the 350 with the AvMap, but I know with my v-8 it's only supposed to display dots not the common aprs symbols)
If you're familiar with Yaesus, the menus while similar are not the same as the other models, so there is something of a learning curve to be had there, I couldn't just tackle it without the manual as was expected.
I know people that have the 710 and they're very happy but want for a 700; and people that own and a very happy with the 350, and want only for the digipeater. As I have an APRS HT, the Digipeater part is key for me; so I'd probably get a kenwood, program it up and have it be APRS only in the mobile or as a full igate as a base, and use other radios for voice, because of the menus, and I'm actually not all that much of a fan of the Kenwood mic (and for those not liking that of a yaesu because they aren't professional, take a look at the Vertex Mics; at which point I probably could have done things cheaper with an OT2 and carefully selected monoband radio (and I've got a whole setup for my ft-270 (OT USB cables GPS etc), and I'll be honest it's so touchy that it's usually not used). If I wanted to becon my location and talk on one radio and didn't care about the digipeating, I'd go with the 350. But also balance what is fact about capability and what is opinion about interface. So I'd suggest if possible getting into an HRO, AES or similar....or at least watching youtube videos of the radio to get a better idea of how they work.