A number of factors come into play when deciding whether to go to law school, including age, marital status, financial status (do you have a mortgage to pay), etc. You know, all that stuff that no employer or school can ask about in an interview.
Regardless of how those factors may play out, given the current state of the market I recommend that you strongly consider exploring the opportunity with the PTO, even if your ultimate goal is to end up in private practice. Some people on this board disagree, but I have found that PTO experience can be a distinguishing factor, both for law school admissions AND for job seeking activities. Moreover, the current market for patent agents and attorneys with no experience is terrible, and may not pick up for several years. And when the market does pick up (I'm still optomisitc that it will), newly minted attorneys will be part of a much larger applicant pool, comprised of all the attorneys and agents from 2009-whenever that could not get a job due to the recession.
Note that there is a "residence" time element to PTO experience if your ultimate goal is to end up in private law practice. Spending a few years as a USPTO examiner will often be seen as value added experience by patent law firms. But once you have spent a significant amount of time at the PTO, some negative stigma may attach. This is attributable to the somewhat negative reputation examiners as a whole have in the professional patent community (however unwarranted that reputation may be).
That being said, being a patent examiner is not a bad career option, provided you know what you are getting into. I've said it before and I will say it again. There are few career opportunities that offer a better work life balance than patent examining. Whether those benefits outweigh the negative aspects of examining (primarily boredom) depends on the particular individual involved.
Good luck in whatever you decide. If you want to chat with someone who has been at through what you are contemplating, drop me a PM.
Best,
Klav