I undestand what you mean a bit.The Su-17 just looks like a "warplane".It has a real nasty look(esp from a front angle).I think it may have to do with the way the nose droops a bit,and the nose intake.One of the reasons I like the look of some russian planes is the they are usualy the result of years and years of progresional development and seem to have a funtion over form look to them.Western aircraft seem more like art somtimes,smooth lines ect. which really wasn't seen in the Communest blck untill the Mig-29/Su-27 generation.One of my all time favorite aircraft is The An-2.It just looks like it was designed by a mechanic rather than a aeronautical engineer.