I've played PN both before and after, and to tell you the truth, I thought it played easier in the new configuration than the old. The greens appear to be a bit less elevated, larger, flatter, and certainly more squared off.
The slopes and swales are still there, but not as pronounced (years of topdressing may have contributed to the look of the old greens).
The major changes to the course were:
1. Lengthening #10 by moving the green back, a change that made the hole much less reachable in two, but still possible.
2. A new tee on #14, making it a ball-busting par 4 of 450+, where it was previously a 480 par 5. Changed from a birdie hole to a very tough and long slight dogleg right.
3. A new back tee on #15, making this 430-yd par 4 play as a par 5 from about 510 or so. This hole went from a very hard par to a birdie hole.
Overall, it is still a great challenge, a great course, and worth a play. To me it represents how it would have played 50-75 years ago very nicely, as many of the greens pre-resto were beginning to get that Pinehurst #2 fall-off look.