I actually prefer this place over Monta for multiple reasons. I enjoy going to Monta every now and then as well; however, Yokohama provides more generous portions for the pricing and has much better variety with a larger menu. The lunch special is amazing because you would expect a smaller bowl of ramen but it's actually enormous! We enjoy the 'combinations' for lunch such as ramen and curry over rice, or beef, etc..
Also, staff is friendlier and they provide quality service. They're more attentive to your needs and extremely polite. We had a female, Japanese server and she was amazing. Even the sushi chef actually custom-made a sushi roll for one of my pickier friends... my friend literally stood up, walked over to him and explained in detail how he wants his roll (he is a bit of a food nazi) and the chef made it with no hesitation. During Easter, I received a free beer from selecting a plastic egg out of a basket that contained a 'surprise' inside. They're definitely a generous establishment. :)
I know there is much hype about how Monta is so great, but I think that only goes to show people will stick to their comfort zone. If you want to try a place that will give Monta a run for their money... definitely check this place out!