What is the best plextor externl available to buy

I have two 716uf drives that I am considering renewing,what advise please

The 755uf, if you can find one.

i have the 755uf and i am very happy with it

Could I use the cases from the 716uf and install a top plextor drive instead of buying a new external?

The 716UF enclosure’s chipset won’t allow full speed burning with the last generation of true Plextor drives (755A and 760A).

Thank you for the info