It is important to figure out what events to go to and which to decline. In most areas there are enough networking events, seminars, workshops, etc to keep you busy all day and night. Busy, yes; productive, no.
The key is to be honest with yourself so you don't overcommit or overextend. I can use myself as an example. I was invited to participate in a new networking group. Sounded good and I strongly believe in networking. However, the group was scheduled for 7:30 in the morning more than 1/2 hour from my home. Realistically, I'm going to have trouble getting there on time. In addition, I already belong to a couple of networking groups.
Reality had to set in and it did this morning. I woke up and realized that while I could most likely get there on time this morning, I probably wasn't going to be able to repeat that every time. That would be unfair to the other people and would shed an unattractive light on me.
Networking works best when all of the elements gel. At some point you should take stock of the activities you are involved with. How productive are they for your business? Honesty here will help you make those tough decisions about which groups to belong to and which to take a pass on.
Bear in mind, it has little to do with the people. And in my case, nothing to do with the people. I haven't really met them yet. I just know myself and I know how to schedule things so they work best for me - so that all elements gel. This wasn't one of those times. It was better to cut it loose before any investment was made.