Generally speaking, the heavier the fabric, the "flatter the lay". You should really stay well under the maximum weights for a firm feeling and comfortable nights sleep.
Please keep in mind the 1.0oz MONOLITE and 1.2oz MTN XL are ultralight fabrics. Even though they offer good strength for their weight, these fabrics will not offer the same durability and long lasting service that the heavier fabrics will provide. Even if you fit within the comfort rating of a particular fabric, it may not be the right fabric for you. If in doubt, go heavier on the fabric and enjoy the added comfort and durability. We stand behind our workmanship 100%, but because of the limited durability of ultralight fabrics in general, we cannot provide any sort of warranty coverage for failure of these lighter weight fabrics. Please use these ultralight fabrics at your own risk.