It never fails to amaze me that people are prepared to travel to Russia and to experience every other aspect of Russian life and Russian-made items, but then baulk at the aircraft and/or Aeroflot.
For what it's worth I organise trips from London to St Petersburg where I can around the odd days when the Tupolev 154 is still on the run with Rossiya (the old Pulkovo). They are great examples of engineering and just run on and on.
Regarding rain coming into the aircraft, that is just not possible as otherwise the pressurisation would not work ! Probably a reference to condensation from the air-conditioning in certain conditions of humidity. I've experienced that in several western types (interestingly never in a Russian one) and thought nothing of it.