I'd been told by a few people that Katsuyoshi (at Ebisu Garden Place, BF2) actually serves better tonkatsu than my beloved Tonki. So, with an open mind, I went to Katsuyoshi this evening. On my way there, I even started drafting my concession speech. Alas, only I shall ever know the contents of said eulogy.
IMHO, Katsuyoshi serves a quite a good meal. But, it isn't a great meal.
While the size of the pork loin cutlet at Katsuyoshi is quite a bit larger than Tonki's, and extremely tender and flavorful, the element that loses them the title of "Best Tonkatsu" is the amount of residual oil on the breading of the cutlet. The cutlet is actually served on a metal draining rack (looks like a cooling rack for cakes/cookies), which allows some of the residual oil to drain onto the plate. Unfortunately, enough oil is left on the cutlet itself to actually be noticible with each bite. And, since Katsuyoshi cooks a lot of tonkatsu in a single restaurant-sized wok (as opposed to the three huge cauldrons used at Tonki), the oil had taken on just a bit of an "old" taste; not really offensive, but evident.
However, the miso soup served with the meal was some of the best I've ever tasted at a restaurant. Definitely better than Tonki's.