I would like to choose both happy and sad.
1. Happy because merit system has motivated users to be more energetic, more constructive, in particular newcomers have tried composing higher quality posts, helping others. On the other hand, higher ranked users found them useful in terms of giving newcomers hints, links, documents to learn, advices to improve their knowledge, skills, etc. It is two-way interaction between them.
2. Sad mainly because merit abusements seem to be occured and discovered day by day, including merit trading, merit exchanging, etc. We can easily found low-quality or even one-line posts which received 20, 30, or 50 merits from one specific sender. It destroys the original objectives of merit system.

To conclude, I highly appreciate what Theymos have done to launch merit system and strongly believe in the system that it will help to clean up and build up the forum as better place for Bitcoin/Altcoins discussions.