Ike's has a huge variety of vegan sandwiches/subs, though most of them are fairly straight-forward (for example, vegan turkey with avocado and tomatoes). I came and tried their Meatless Mike's ($9), which won PETA's "best meatball sandwich" award.
Make sure to specify you're vegan, as they have a lacto-vegetarian version as well. Also, their wholewheat bread option is the only one that's not vegan, which is a shame, but I'm happy that they told me this immediately and were aware of the fact.
Expect long lines at peak lunch times, and expect to wait 5-10 minutes for your sandwich to be made. If you're in a rush, this is not the best place for you.
I got the sandwich on some bread they call "dutch" something. It was basically a white, flaky-crusty bread and, while it had good texture, I couldn't get it out of my mind that it's white flour (I hate white flour). They also have sourdough and gluten-free breads.
The sandwich was good overall and the portion size was substantial. It seems like they use Matt's brand meatballs (which you can get at Whole Foods and some mainstream grocery stores), which taste fine, but I'd prefer it if Ike's made their own. The marinara sauce was good, but I wasn't a fan of the vegan cheese (I think it was Teese); it didn't add anything to the sandwich.
Daiya vegan cheese would have been better but the best option would have been to do a cashew-tofu nut cheese with herbs.
Honestly, while this sandwich was good, it wasn't even close to as good as the Mock Sausage Parmigiana that you can get at Pizza Luce (a small chain in the Twin Cities). Luce makes their own "cheese" and it's more like a savory, addictive pate that complements tomato-based sauces perfectly, not least in part because of its use of fresh herbs.
In comparison, Ike's just gives you some straight-up marinara with straight-up Teese mozzarella. It's much less sophisticated and, sadly, less tasty as well.
All that said, I applaud Ike's for being so vegan friendly and I look forward to trying other sandwiches they offer.