I really dont see a point in comparing past with present,if they can satisfy some minimum like a band it is ok for me,they are like band,playing wise,great for today standards in music,all old bands are,you can see that -metallica,maiden,guns,whitesnake,U2,foreigner,purp le,aerosmith etc.
Only problem is Jons voice,for someone is solid, for someone shot,but when you get the whole picture from the show it is not the most important thing to get good times and enjoy the show.