Depends on what you need- I turned down a similar trade (before eventually trading my MD as part of another massive trade):

Do you lack analog drum sounds?

Do you need a drum machine that is also a 6 voice analog polysynth? Nice to have.

Would you miss the sound and character of the MD? I do, but I won’t replace it with the current gen. MD. Waiting for the next.

Do you like building drum and synth sounds of your own? Or would you prefer a large bank of preloaded samples/patches.

What kind of music do you make? Tempest can sound far more traditional than the MD, but the MD can sound much more alien and evil.

Do you just want a drum machine that you can program real quick and move on to other things, making small tweaks, mutes, etc. along the way? The MD is that, the Tempest is not. It’s much more time consuming.

Honestly, the trade works out such that you could try the Tempest and then sell it and buy an MD back if you want.

You really have nothing to lose.