I notice 21" CRT monitors coming down in price, now that LCD's are taking over. Sony seems to have the best 21" CRT's. They seem clearer. If I were to buy an older model 21" Sony which one would you use? Sony Stylepro CPD-E540 Sony GDM-500PS Sony GS series Model 520 Sony CPD-G500 Have I missed any Sony models....do you find that maybe a NEC or a ViewSonic to be just as good? Michael B.