During this first bonus year, I spent just over $30k on the Delta Reserve in order to get both the MQD waiver and the first annual miles boost. I decided to stop using it after that because it didn't feel worth it to me to spend another $30k for the second miles boost, given the opportunity cost of getting UR or MR points on those purchases instead (I do not have the time or inclination for manufactured spend). There is zero chance I would attempt the $250k Diamond MQD waiver.
If I kept it for another year, I would probably try to hit the $30k again but not the $60k. Even the first $30k is a bit of a tough call for me, however - I'd be giving up $450-$1350 worth of Ultimate Rewards points (1.5% on regular purchases if redeemed for travel and 4.5% on travel purchases if redeemed for travel). The difficulty is that it's hard to put a number value on status, but UR/MR points are very easy to value in dollars and cents.