I went to the most convenient Choshimaru to Tokyo, which was closest to the Suidobashi subway (but I'm not 100% sure, I will need to double check) and was a 15 min walk or quick bus ride from the station.

The location was quite large, and while the sushi was a belt setup, nothing was on the belt and you ordered from a nearby chef in the large central area in the middle of the belt. This was definitely a locals-only area and restaurant, although as part of a chain, they had an English menu but I was with a Japanese friend.

Quality varied widely - some pieces were probably on par with a $300 sushi restaurant in the US, some were on par with any decent-average sushi restaurant, and some were - well- just not cutting it. The smoked bonito failed miserably to the version served by Jiro-san, yet the various saba, tai, iwashi, tobiko, ikura and even fresh salmon were all very, very good. Here, the simpler and local fish shine, the more complex creations tend to fail.

The toro was a crime - a piece of silky, buttery fully marbled toro was cut into a thick slab instead of a delicate slice against the grain designed to melt in your mouth - so what should have been an incredibly delicious piece of toro, for US$2.50 no less, was reduced to a mix of heavenly, buttery smoothness with too much sinew to work through. Had it been cut properly, I would have just had an endless supply of this for such a cheap price. Uni was sold out, so I wasn't able to try it.

Two of us stuffed ourselves almost unconscious for a total of US$50 - even with some mediocre pieces, the overall quality was excellent. I think the next visit will be to one of the smaller single-location places in my post upthread, or just return to my usual Zanmai location across from Shibuya Station.

One word of note - the sushi is all pre-cut and stored in large containers for volume service, this is not chef-cut sushi prepared to order, just assembled to order.