By default most of the games on a PS2 are going to be 480i, and while I’m a huge fan of the OSSC, its deinterlacing is… concerning. For me personally it causes some serious (though so far temporary) burn in on my monitors due to the high flicker rate. So if 480i is your primary use, I wouldn’t recommend it personally.
On the other hand, feeding it to pretty much any other de-interlacer, and THEN to the OSSC as 480p looks great. This is especially true if you want to add scanlines, or if you have a final processor or display that handles 480p x2 mode (with or without scanlines).
I have a DVDO Duo and I’d recommend that over the OSSC if it was exclusively for PS2, they can occasionally be found for a decent price.