If the porcelain toilet cracked, as mentioned, the first thought is the bolts may have been over-tightened. Hopefully you won't find the flange damaged.
We had plastic in the past and now have porcelain. Would never go back to plastic. Porcelain toilets are much easier to clean and will stay much cleaner. No nasty skid marks to clean all the time. If plastic was better, you'd see them in houses but you don't.
I also think porcelain is quieter and you won't hear the tinkle tinkle from DH from outside the bathroom like with a plastic toilet.
Consider an elongated bowl like the Dometic 320 or Thetford Aria deluxe - most people prefer elongated bowls nowadays plus there is more room in these for male anatomy.