the two headphones are very different from eachother, the only similarity is that they're both closed. I have HD 25-1's myself, and a friend of mine has the 250 linear II's. I have had only a brief audition, and found them somewhat pleasant, airy but very bright. The HD 25-1's are much warmer, with big bass and a much less airy soundstage. They are somewhat similar to some Grado's in that respect.
The main reason that you see the HD 25-1's mentioned left and right is that they're ideal commuter headphones: great isolation, good and fun sound, rugged construction and no-nonsense styling. As for the 250's .. well I guess you'd better ask in the
main headphones forum. They'll probably tell you that neither are the best choice for home listening. The 595's for example are much better suited ..