Titanium does have a lower thermal conductivity, but heat transfer is proportional to thermal conductivity divided by wall thickness. Titanium pots tend to be thinner than aluminum so it is not clear which one will have better heat transfer. Based on anecdotal evidence from various people my guess is that pot material is pretty negligible in terms of how quickly or efficiently you will boil water. Pot shape, windscreen use and fit, and whether your pot has a heat exchanger play a much bigger role in bringing water to a boil. I would guess even the radiative properties of the pot play a bigger role in how quickly you boil.

If you really want to put some numbers to, you can look up thermal conductivity for various materials on: http://www.matweb.com/

I looked up a typical aluminum and found a thermal conductivity of 180 W/m-°C and 6.7 W/m-°C for Titanium. I couldn't readily find wall thicknesses for various pots. If you can get that info, just divide the thermal conductivity by the thickness and compare.

Your's is the first report I have heard of a titanium pot become more slippery on a stove than an aluminum pot. That is interesting... I have no idea what is causing that. You could try roughening the surface to make it more grippy (it would also improve the radiative performance of the pot!).