I have recently bought a Virus TI keyboard after playing the Korg R3 and the Nord Lead 2 for a very long time, and I noticed that the portamento of these three synths functions quite differently. The portamento curve on the R3 is linear, but NL2 and the Virus use something like logarithmic/exponential curves. Every one of them is good for achieving different things when designing a sound, and I would find it very useful to have a choice between at least the one that the Virus is currently using and a linear curve.
Thanks for listening, Access!
EDIT : I just found out that there are more threads about this, sorry for spamming.