I Need Your Opinion!

So I got word today that the BV is officially "mine." That means that I'm one of the two operators who will be the primary BV operators. Which is exactly what I wanted from the get-go. I'm really pleased. It's relaxing, fun, less maintenance, good all around.

Then my boss asked me what I wanted. Do I want a 3 day work week or 4. I have seniority over the other guy, plus he doesn't care. All along, I've thought I wanted a 3 day week, but now I'm really leaning towards 4. I need your help.

3 day week: 3, 12.5 hour days, getting paid for 13 (you work through lunch). It's a 4 day weekend every single weekend. The long shifts make up for the fact that it's not 40 hours of work, but I'd be on the books as part time, which would mess with taking vacation time, and a few things like that from the HR perspective. Financially, it's 10 hours regular time and 3 hours overtime (time and a half) each day. For simple math's sake, let's say I make $10 an hour (thank dog I don't!).
10 regular hours=$100
3 hrs @ $15/hr=$45
$145/day, times 3 (work days)=$435. This number, at my actual rate of pay, comes out to be a bit more than a 40 hour week at my current salary. It'd be as if I worked a 43 hour week.

4 day week: 4, 12.5 hours days getting paid for 13. I'd work 50 hours, every week. I'd get a three day weekend each week. My vacation time and all that would be based on a 40 hour work week, not a 30, which means I wouldn't lose as much money taking time off. I'm worried about the exhaustion factor. With driving to and from work, I've only got about 10 and a half hours each work day that I'm not at work. that's pretty severe. Can I handle 4 days of that in a row? Is there that much of a difference between 3 of those days and 4?
The money breakdown:
the same $145/day, but times 4=580. that's a pretty substantial difference, when you do the real math for my actual salary.

I talked to the Big Boss today, and he seemed to be pushing me towards the 3 day week, but when I asked him if he had a shift he'd prefer for me, he said he didn't care. A guy I'm friendly with in the office said I'd be a fool to not do the 4 day week, that the money makes up for the time, and reminded me that I could either bank that overtime to use as time off down the road, or add it to my paycheck each week.

Considering the fact that with most jobs in my field that I'm applying with, I'll be needing to move pretty quickly after taking the job, and it'd be nice to be able to save some money. But a 4 day weekend, especially during the summer, means I can go wherever I want to go, every week. 4 days off, and it's so easy to spend a weekend at my sister's. Spend a weekend with friends in the bay area, or the northern CA coast.

So, lovely blog readers, HELP! Thinking bigger picture than JUST dollar signs or time off, but the whole picture, what would you do? What should I do? I need advice!