Oba is a really swanky place and definitely a great place to take a date. The bar is modern and funky, whereas the dining area is a bit more romantic.
The service is top-notch and really friend, from the servers to the hosts.
While the vegan options are limited here, Oba does have a separate vegetarian menu if you ask for it. I got the tacos dinner modified to be vegan ($12 or so): it was tasty, but really basic. Given that we're in Portland, I would have hoped for a vegan mole sauce, or maybe even just some grilled tofu and seitan.
I also had their guacamole, which was decent, but could have been a bit more savory (I think it needed a bit of salt, and a little more lime).
There are no vegan desserts (other than sorbet, which is so boring as to not warrant attention), sadly.
On a whole, not a bad place. I'd come back for a drink, though the vegan food options aren't interesting enough for me to justify another full meal here.