Bikram and have been using a 3 mm mat which is now well due for replacement.
I am wondering if it makes sense to aspire for an even thinner mat, i.e. if it is better for you to practice on a skinny mat, i.e. go for 2 mm or even less.
Purely a 'by experience' answer here, having tried both:
Advantages of a thinner mat:
Advantages of a thicker mat:
The thickness of your yoga mat has a lot to do with how comfortable it is — too thin, and your knee may get banged up during crescent lunge. The tradeoff is that thick yoga mats (some as thick as 1/4 inch) can make it harder for you to feel a strong connection to the floor, making you more wobbly. Otherwise, it really just depends on whether you want a bulky mat to be carrying around.