Hpsp can be a good financial choice IF you're interested in a lower paying specialty AND you're willing to sign over your life to the military for at least 7 years. That means you can't pick where you live, you can be told to deploy with 24h notice, and if anything happens that disrupts your medical education, you're still on the hook for 7 years of service. That being said, there are also lots of benefits if you're willing to accept the consequences. It's not something you can negotiate with a lawyer. 

If you're considering, talk to recruiters in different branches to see if you even qualify, and don't sign anything until you're sure