Help with counteroffer from a company I rejected

I recently went through the interviewing process and decided to go with an offer from a smaller stage company (a few billion dollar valuation). After a few months of work, one of the companies I rejected contacted me saying they’ve changed their comp policies and basically extended a much much better offer. The money is tempting but I do like the company I’m at right now. I wish I had the better offer earlier so I could’ve negotiated with it. How would you think about/handle this situation? Would you take it / try to use this to negotiate with your current company / let it go? What kinds of questions would you ask yourself? TC at smaller company: $650k first year. TC at rejected company: $750k first year, but the cash portion of the package is nearly double that of my current cash portion. With refreshers, by the 3rd year I’d be bringing in almost $1 mil/year TC. This company is much larger and more established, and while not public, I feel very confident about its equity value.