If old school means primitive, then I wouldn't say I prefer that, it can be nice on occasion though. If old school means traditional, that's more towards what I like. Technical can be good (ie. Death), but the new school of über-brutal hyper technical stuff doesn't do much for me. Generally I do have a preference for a certain level of sophistication in my music, Death Metal included.
I like quite some classic melodic (Swedish) Death Metal as well, Dissection, Eucharist, Dark Tranquillity, Unanimated, classic In Flames etc.