I agree, I have used a lot of bergers, from the 140 out of a 6.5 up to a 300 from a .338 to take elk, and lots in between. My current elk rig is a 30 nosler with a 208 Berger. I have also used lots of monos. In the 6.5, I have used the 140 vld, 147 eldm, and 156 Berger. The closest elk I have killed with them is 610 yards, the farthest is 890, and surprisingly the only exits were with the 140 vld. Of the other bullets recovered, no evidence of tumbling was present. I haven't shot any gel blocks, but we have documented around 35-40 elk taken from 300-1036 yards, averagjng arojnd 800, with a lot of different bullets. It is obvious the Bergers are a fragmenting bullet, however at the lower impact velocities I typically use them at, they perform a lot like lots of standard, non bonded/partitioned cup and core bullets do at standard ranges. Before I started shooting long range, I used a lot of hornady core lockts, nosler ballistic tips and sierra game kings, and at sub 300 yards I typically used them at, they perform very similarly on game to bergers at range.
In our testing on pronghorn, we have somewhere around 100 speed goats we have taken with 6.5, .277, 7mm, .30 and .338 cal bergers. The 6.5 is by far my favorite on them, and my results from that has tempted me to build a 6mm for them, however shots often extend out to 800+ yards, and almost always have wind to consider, so I don't want to go too far down.
I used to look at ft lbs as my limiting factor, but have since modified that, I still reference it, but I pay more attention to impact velocity, and using the right bullet. For instance, if you solely go by ft-lbs, a 300 Berger out of a .338 still has 1500 ft-lbs when impact velocity is below 1600 fps. I have heard some say 1600 is the threshold for the bergers to expand, but I personally prefer a buffer, and try to keep it above 1800. I can also make 1500 ft-lbs with the 156 Berger out of a 6.5 at 2080 fps, and from my long barreled .260ai at the elevation I hunt, that means a 900 yard shot on an elk is within that range, so good to go right? (I have done it, you can, but it is not my preference) This is where the using the right bullet side comes into play.
Bottom line from my experience, is there is a very large depth and breadth to game terminal performance. And all of this isn't even taking into account the vast differences in monolithic style bullets! They are a different animal (not necessarily better, just different) and require different sets of parameters and limits. Lots of considerations, good thing we have options!