480 was faster than 5870, are you talking about 470?
The 480 was faster, but it was largely panned on release due to heat and noise issues - while the 5870 was far more efficient. It should also be mentioned that the 5870 was released 7 months prior to the GTX 480.
The GTX 580 was everything the 480 *should* have been, it was a great product. But, I was not impressed by the 480 at release. If you go back and look at reviews, this sentiment was shared among many - it was a hot and loud piece of junk. That is why many folks stayed with the 5870 and/or preferred it over the 480 despite the slight speed deficiency (besides the fact that it was released much sooner than the 480).
I really feel like Fermi is why nvidia pushed so hard for efficiency with the Kepler. That was the smart business move by nvidia, nobody wants a dust buster for a GPU. Seems like the roles are reversed these days. AMD/ATI were always the more efficient uarch prior to Fermi. Again, nvidia made the right move by focusing on efficiency with the Kepler; I don't care about power consumption but I
do care about the indirect effects it has on heat and noise.
I do think the 9970 will match or come close to Titan - but the most important thing in my mind is for AMD to ensure the software is up to snuff and creating an improved reference cooler. AMD used the same ref cooler from the 5870 to the 7970, it really is time to junk that reference cooler. It is long in the tooth to say the least. Really, those were the biggest problems with the 7970. It was a good product in it's own right but it took f-o-r-e-v-e-r for the software/drivers to catch up to it. That cannot happen again IMO.