True, but the Ti was always used really on the lower end cards and as you said the Ultra cards were the top cards with an extra overclock normally and maybe a little more VRAM, but the chip in most Ultras was a full chip with only a better bin that would overclock more but no extra cores/shaders normally. That's why Ultra cards also got a bad reputation because they were normally the same hardware with an overclock that most would mod their cards to overclock the same.Before that the equivalent of the Ti cards were the Ultras - though the GeForce 3 and 4 series did have Ti cards including top end cards like the GeForce 3 Ti500.
It's actually funny how Nvidia has not used the Ultra name on cards since .. The joke back then for top end Ultra cards was Ultra rip off, I even remember toms hardware and the review sites back then and pc magazines telling people to avoid them and get the card down for way less.. Again was Nvidia testing the market what people would pay for the so called best. They have done this game many times as we know, Titan cards are a perfect example of that.