Hi Ahdat---
I don't own the 890s, but as I listen to the 280s more and more, I feel they are much more musical than the V6s, though also capable of being used for careful monitoring of music; the 280s in effect have the both of best worlds.
I would say the following should decide you on 280 or 890:
1) location. If you are in the US, your only source to get the 890s would be to order from Jan Meier in Germany. This will cost you about $115 and a 3 week wait. If your local Virgin has the 280s, you can get em for $99 (plus tax) and can bring them back easily if there is something wrong or if you just don't like them. If you are outside the U.S., and can get the 890s more cheaply and/or easily than the 280s, than that should decide you.
2) portability. If you ever want to use your phones outside the house, the 280s are lighter, smaller and fold up. On the other hand, if your sole intended use is the house, than the Philips would look nice with their headphone stand.
3) need for isolation. If you need isolation from your surroundings, get the 280s. Otherwise, open headphones for the same price (i.e. the Philips) will probably sound better (though I am generalizing here as I have not yet heard the 890s)
Ultimately, if you don't mind the international ordering, don't need portable phones, and don't need isolation get the 890s. I don't think you could really go wrong with either phone. The only criticisms of the 890s have come from a few audiophiles who have collections of much more expensive cans, and the only criticism of the 280s seems to have been based on very early models of the phones that have later been modified.
Let us know what you decide and how you like your purchase!