To figure out the finances to make a comparison for your situation, and assuming you're going for a 4yr, lay out all 8 years to figure out what's better. Make sure to factor in taxes with both.
For HSCP:
Years 1-4 in school: BAH in the area of your school+ COLA if it is an eligible area + BAS + Basic Pay (note pay goes up after 2, then again after 3 years).
Years 5-8: BAS + bonus + BAH (for a base somewhere) + Basic Pay (4+ yrs).
Some factors may change, such as if you are able to recruit, your pay in school will go up to E7, or if you have dependents - spouse and/or kid your BAH goes up. But this will give a good view of the overall pay.
For HPSP:
Years 1-4 in school: Tuition/fees + Stipend + 45 days AD O1 pay per year.
Years 5-8: BAS + bonus + BAH (for the same base) + Basic Pay (0 yrs)
Then also think about HSCP will not cover the cost of loupes, boards, books, etc. In addition, I've found that there is a lot more hassle with HSCP - long drives to military installations for physicals which may require multiple visits, physical fitness tests, collegiate meetings, drug tests, weigh ins, monthly paperwork, and if you want to travel abroad while in school, a hugely painful leave application process that requires hours of trainings (among other things). Although I haven't tried to accomplish this, I've heard that doing an externship at military sites is also more complicated with HSCP than with HPSP. You do get a CAC card and can access the commissary and get military discounts on HSCP.