Powell,
Good question. The responses by Tommy and Jim are timely as well given they relate to the holes you mention.
The 11th hasn't really been impacted. Some higher handicappers probably hit drivers on the hole and they probably still do. For the longer hitters and lower handicap players, the tee shot was likely a 3 or 5-wood and today is probably a 3 or 4-iron or my choice from the back tee, a 7-wood. The way the modern ball behaves with iron shots makes the approach shot to the 11th green easier, but the firmness of the green and the green speeds (not necessarily related) counter the better performing balls and grooves.
As for the 12th hole, the new back tee length requires most to hit a driver or maybe a 3-wood for the longer hitters. From the middle tee, I hit no more than a 3-wood for a full 8 or 9-iron shot into the green. The hole remains very difficult because of the slope of the green, the green speeds and the green firmness. The enhanced maintenance practices keep this hole from being easier than it used to be with softer conditions and slower green speeds.
In addition, the use of rotary mowers for the rough makes the grass stand straighter so that even shorter rough today plays harder than the reel mowers that tended to lay the grass down. The way rough is being maintained...firmer and much thicker, means that balls off line go further off line and are harder to recover from than they used to be.