Site.pro recommends On-Premises license because of stability reason:
Website Builder is stored on your server (in your country) so it will never be affected:
by local or global internet shutdowns (e.g. Pakistan, Kazakhstan, Iran, Belarus),
blockages (e.g. China, South Korea),
data storage regulations (e.g. Russia, Europe, USA),
smaller ping between builder and clients' hostings (a faster website publication time).
Prices are the same (for On-Premises and Cloud);
On-premises has additional features and much more customisation options.