Microfiber has an interesting feel to it that some might like. It adds variety to a wardrobe. It's not a must-have, but as a synthetic, it is a much better choice than polyester. To answer that other question, tencel is better. Pardon the hyperbole.
TENCELÂ® heralds the beginning of a new age in fiber technology. Completely natural, TENCELÂ® is Lenzing Fibers’ brand name for lyocell. A major break-through was made with the development of the unique nanofibril structure of this fiber. TENCELÂ®, made from wood pulp cellulose, offers a unique combination of the most desirable properties of man made and natural fibers: soft as silk, strong as polyester, cool as linen, warm as wool and as absorbent as cotton. Quite simply a “break-through” fiber.
It's still a bit pricey and hard to find, but having a shirt or pair of pants made of tencel is recommended.