Airplane differences would include;
engines have 2 spools and use N1 to set power and therefore have no EPR indication.
engines have 3 spools so you will have an N3 indication plus EPR.
have 2 spools and EPR.
Other differences would include take-off power, cruise power, fuel consumption, and noise. There will be slight differences in all of these that might be considered.
With the US not very popular in many places, RR
could have a political advantage.
Depending on the location where the airplane is to be hangared, the availability of good technical service might be a consideration.
Would one engine manufacturer provide a better price and service package to the owner/operator?
Plus the personal preferences of the buyer will come into play. People at that income level generally have distinct biases that they don't have to mask.
It's the golden rule. "He who has the gold makes the rules."