I've been using a KR1 for about 2 years, and the TopGlobal MB6000 for about a year. These things are great, but buying any 3G router off the shelf without any preplanning may not work out.
With every previous 3G router, you need to make sure it supports your device. Firmware upgrades typically increase the number of supported devices.
The PHS300 has no Ethernet jack. That might be an issue. I run VPNs, audio, video; pretty much everything short of P2P through EVDO and have had video (ie streaming, flash video, etc) problems (at the router) when connecting 802.11. I've also had VPN issues via 802.11 that go away when I go Ethernet.
Audio, browsing, etc. don't seem to be a problem.
Anytime you plan on tethering your phone, you should look at your provider plan. Some folks have signed up for a web upgrade package for their phone, but not the full 3G option, and then tethered their phones. Some have been booted for doing that. Others haven't.
I'd visit »evdoinfo.com
and see if someone has used your provider the way you want to.
All in all, I love these things. Once a month, I take an entire company to a remote location for 4 days for a retail event where reliability is crucial. The time, money and trouble we save on getting DSL or (Ack!) dialup pre-prepared is worth 5x what we have in this setup.
I also dig my van being a mobile hotspot; albeit a secure one.
My children used to Speak in Tongues. But after years of Speech Therapy, English is their First Language!