After 18 months of use..,
This review is from: Microsoft Comfort Curve Keyboard 2000 (Accessory)
This keyboard started out very efficient and comfortable, but after using for 18 months certain keys don't work eg "m" etc . I goggled the problem and it seems to be a common flaw.
I bought 4 for use in my small business and the first was binned after year one and now the second one is going into the bin too. The remaining two still work fine.