We have a 2014 TEP 4Runner that we purchased new, now has about 160k miles on it, along with our 2008 4Runner that we've owned since 2008.
The 5th gen feels bigger, the interior is fancier, and it looks newer (duh).
Both of mine are 4.0's but the 4th gen throttle and transmission tuning are much better. The 5th gen feels like a slug compared to my 4th gen. Most of the time I drive the 5th gen in "sport mode" which at least helps negate the awful transmission tuning. Both 4Runners have been very reliable but both suffered from a stereo failure and I've upgraded the stereos to something better anyway. I feel the 4th gen has better visibility when looking outside than the 5th gen. The AC in the 5th gen seems to cool a little better than the 4th gen but that could be age difference and color difference (4th gen is black, 5th gen is white).
Offroad, our 5th gen has a factory rear locking diff that really helps on the tuff trails and a manually shifted transfer case. The 4th gen has the electrically shifted, center locking torsen differential t-case that I've grown to love. 4-high without the center locked works really well in most conditions. My 4th gen turns tighter than the 5th gen but that could be the difference in UCA's and alignment specs.
Long story short, after all these years/miles, I like driving the 4th gen more because I like the throttle response and transmission tuning better and it feels smaller and a little more nimble, especially in tight city streets that I unfortunately find myself on most days.