166/month for that plan is very not bad. Looks like everyone here has covered a lot of the points that need covering. Couple things though:
Not to ask for specifics, but do you take a lot of medications? If not, then you could probably get a plan with higher co-pays on prescriptions and that could lower your monthly. The prescription co-pays listed on that plan are actually pretty good for these days, and it is a nice low annual deductible.
Same deal for your office visits, the 20/primary and 30/specialists is pretty decent, so the question is do you go to lots of appointments? I think someone else already mentioned this but, the way that plan is set up your co-pays are pretty good, but if you go to lots of appointments each year you will be paying a lot since there is no deductible.
Choosing a plan is all about the long view. Balancing out your co-pays/deductibles with your monthly payment based on how often you go to the dr. For example, I rarely go to the doctor so my plan has relatively high co-pays/deductibles but a low monthly cost. And again, if you DO go to a lot of appointments, you want some kind of deductible on those or you can end up paying a LOT over the course of a year despite low co-pays.
Two more things you need to investigate. As others have mentioned, you need to get a network booklet from Keystone, or search for your current doctor on their website.
Go Here and click on "Find Participating Doctors, Hospitals, and Ancillary Providers." With an HMO, you have to choose a primary doctor who belongs to their network, and whenever you see a specialist (also in network) you'll need a referral from your primary. Thankfully, this has gotten easier than it used to be as it is all electronic now. Although that doesn't mean they still don't forget to send em sometimes, they can send another one easily with a phone call.
Finally, I noticed you didn't list the emergency coverage. With any plan, you should see what kind of financial mess you can get in to if you have to go to the hospital. That info should have been listed with the other stuff you quoted in the original post.