Not really.

The moderate beauty doesn't outweigh the extreme crowds.

I would recommend HuaShan (near Xi'An). It is steeper and somewhat more beautiful than TaiShan. Unless you have the leg muscles of a raptor, though, the initial climb is quite taxing. In hindsight I'd take the cable car instead (especially when descending). There is still a lot of walking to do between the five peaks, and you will have more time if you took the cable car.

If you plan on visiting either, I would also recommend going when it's raining to avoid the masses.

I thought Taishan was great. Pretty tough climb - I did it from the very bottom to the top and it took me about 8 hours, and the last section where it's pure stairs and a steep incline is pretty gruelling. Still, we got to the top when the sun was setting and it was gorgeous, and the view also when the sun rises is worth getting up for. We stayed on top of the mountain in a pretty grubby hotel (where they had epically expensive food - remember to bring your own) but the trip itself was pretty worth it.

Imagine the busy subway on the train during peak hours except you are actually climbing, that is my answer