The only possible downside I would see, assuming they are paying for it, is that the potential exists for it to be counted against you if you need a policy for the benefit of your family. In some cases, some insurers will only cover a certain multiple of your income at their best rates. If you need a new policy, they may count the existing coverage against you, and you would end up paying more.
That said, I'd be very comfortable saying to your boss, "Hey, I'll let you cover me, but I'd like you to also set aside a portion for my family as well. At a certain point, the premium increases for the extra will be nearly negligible for the company and yet beneficial to your family.
Also, as alluded to in the comments, insurers may incentivize the purchaser if you fall into lower risk groups. They may pressure you away from riskier habits (smoking, sky diving, etc.). You are under no financial obligation to adhere to these, but politically it may become compulsory. That said, if you want to become a pilot (higher premium) you may need to tell your employer first.
Oh, and if the conversation starts with, "Mr. Soprano," you may want to investigate one of those dead man services that emails your secrets if you don't check in every day. :)