The key for me (and it isn't an issue for me this year - I'll just stick with my 1P MM for the time being given this year's budget and travel plans) would be "How valuable will the SWUs be for me next year? I'll tell you that from recent experience of not having SWUs, my "quick weekends in Europe" are not happening anymore. Also, given how mileage-expensive an upgrade is, my now more-limited bank of miles is used for free premium-class tickets. (This is a similar boat you may find yourself in if you don't requal. 1K). I'd also consider what my domestic travel plans are likely to be in the coming year, i.e., routes 1Ps rarely get an upgrade, routes there are mostly A319/320, Ted routes, etc.

Once upon a time, I would have thought the sky would have fallen if I fell out of 1K land after 8 or so years of it. But as a MM (which adds another dynamic to your basic question), the sky has not fallen, I am taking fewer stupid trips, I am still treated with a modicum of respect by the company, and my domestic upgrade % isn't completely dismal. I'll admit it is a shocker when that 1P card comes in the mail, and when you aren't at the top (or near) of the upgrade list, the mealtaking order, and so on. But you know, it isn't the end of the world