I countered their offer, asking for more salary and PTO using my current as justification. They bumped the salary up to $5k short of where I am now and tacked on a $5k signing bonus. As far as PTO, I provided dates of vacations I have booked already, they are going to exclude those from the standard PTO. They also increased my stock options.
So, after one year it nets out to roughly the same as I would expect from anywhere else. If their product takes off, I have the assurance they will re-visit their benefits package (including PTO which they know sucks)...and I will be in a position for a promotion, and I will claw back that salary I'm giving up now. No promises of course, but there is real potential for exponential growth.
If things don't work out after a year, I find something else. Not a big deal. I know my skills are marketable and transferrable, so I'm not afraid to take a chance. And, a one-year stint at a tech start-up would not hurt my resume...at all.
Also, in one year the non-compete I have with my current employer expires, so there's that.
I'm going to accept the offer as soon as I can understand the prospects of the options.