It is in no way a perfect deal for either team. As a pitcher, Ishii is almost the polar opposite of Trachsel. Trachsel is a pitcher of extremely limited talent who gets the most out of what he has by pitching intelligently. He's crafty, and he generally gives a team a lot of innings, something the Mets were desperately counting on given the state of their bullpen. Ishii, OTOH, has incredible stuff. He's often unhittable, but often the reason he is unhittable is because his pitches are nowhere near the strike zone. He was a roller coaster last year, sometimes brilliant, sometimes sent to the showers by the fourth inning. He was demoted to the bullpen a couple of times, only to be thrown into the breach again and again because of injuries. I predict interesting times ahead at Shea.
Meanwhile the Dodgers' catching was a disaster waiting to happen. Until today, they had no major league catcher. Neither of the guys who were supposed to be the platoon at the position this season, David Ross and Paul Bako, have yet been able to prove that they can hit major league pitching. The only difference between them is that Bako does his non-hitting from the left side, while Ross doesn't hit from the right. The Dodgers had three minor league catchers in camp as well, and all three have hit better than the incumbents. Russell Martin has been the most impressive of all of them, but at 22, still needs seasoning, as does Dioner Navarro. Martin has already been dropped down to the AA squad. Navarro will probably start the season in AAA, which leaves Mike Rose, a non-roster 28 year old minor league veteran who has outhit and outplayed Ross and Bako this spring, although probably not enough to unseat either of them.
Now we throw Phillips into the mix. On any other team, Phillips would be a serviceable backup. Here, he is the best of a bad bunch. He has shown he can hit major league pitching a little, doesn't strike out a whole lot, and is patient enough to take a walk. He's not great defensively, but neither are Ross or Bako. The important point here is that he hits well enough that Jim Tracy doesn't have to think about having his pitcher bat eighth, or having his fifth outfielder strap on catcher's gear in the late innings (Tracey had Jason Grabowski catch a few innings this spring, just in case).
Now the question is who will be the backup? I suspect Bako has the edge because he tries to hit left-handed, but I'd really prefer to see Mike Rose hang on.