One of the major cons about operating Russian aircraft is spares. In South America, Peru, Nicaragua and Cuba all operated Russian aircraft (Cuba still does), but after the break-up of the USSR
acquiring spares became a nightmare and in most cases aircraft had to be cannibalised locally to keep others flying:
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Photo © Girmay Tesfay
Peru experienced major headaches when it bought 19 MiG-29s and 18 Su-25s from Belarus in the mid-90s. MAPO MiG refused to sell the Peruvian Air Force spares as the aircraft were not bought direct from Russia. In the end, Peru had to buy a couple of each from the manufacturer and then, low and behold, the spares started flowing into Peru. In just a few years however, Peru discovered that their MiGs and Sukhois were actually in a very poor state, and several have crashed. And now Brazil wants to buy Flankers...
Unless an airline is bankrupt, is delayed on lease payments, or happens to be called "Iran Air" or "Libyan Arab Airlines", there are generally few if any problems experienced when trying to acquire spares from Boeing, and with France's political flexibility, there are virtually NO problems in securing spares from Airbus!
Seriously, it's a matter of convenience. Russian aircraft have become pretty reliable, but are too damn slow off the line. And these days, with the snail pace of airliner production in Russia, it is no surprise Ilyushin and Tupolev are doing so badly vis-a-vis the Il-96 and Tu-204/214. Airlines hate waiting!