I've been here twice and it's been really good!
The first time I came it was just two of us and we waited about 1/2 an hour. The second time it was a group of six and we waited probably an hour total (or at least one of our party waited an hour). This place is pretty small and I was hesitant with six people, but it worked out in the end. You probably shouldn't do more than six unless it's dead and both times I've been it was obviously busy (hence the wait).
However, once you get inside and order your food comes out relatively quickly and it's very tasty. The price is also quite nice because for being such a busy place they could probably charge a bit more (like lots of other ramen places) and still keep he crowds coming in.
Overall, I enjoy Monta and I'd probably go back, but maybe just as a group of 2-3.
Kimchi fried rice is so good.