I can.
On a 2x2, looking at about 12 seconds average solve.
On a 3x3, using fridrich method i can get about a 25 second solve, so pretty quick, depending on how the PLL and OLL decide to act, and if theres any parity errors or anything like that.
On a 4x4, i can get about a minute 20 to minute 40, depending on how arranging the middles and orienting the edge pieces go.
On a 5x5, im at about 4-5 minutes, reason being that my outer pieces dont rotate worth shit and also I just started with them so its a little new for me.
I plan on getting a 6x6 vcube and a 7x7 v cube pretty soon too.