I hate to say it, but this Jeff guy is fairly cluesless when it comes to Unity. And is, therefore, in a poor position to give any useful insight into Unity vs. UE4.
My studio (of roughly 27 years) has used a lot of tech in its time. We even developed our own engine, HeroEngine (used in games like Star Wars The Old Republic MMO). We've made lots of games and have lots of experience with Unity. I used Unity to do the Android port of Temple Run, and we've made a lot other titles with it too. We're currently working on a marquee franchise for a major publisher... using Unity.
Unity is not just for small teams. Jeff didn't do his homework on this one. Our team is 27 strong, using git for version control. We use a deep feature-branch approach and it works well not only for our developers, but our non-techies: artists, designers, sound guys, etc. Sure there are issues with Unity and version control, but you find ways to make it work through convention and approach. Same thing happens in all Engines. They all have their issues. The only engine that put collaboration at the forefront was our HeroEngine, but even that has issues. Though we sold off that tech, you can still check it yourself... just Google.
The 32 bit editor limit is true, but is it really an issue? It never has been for us. His problems smell strongly of bad development practices... they can't seem to manage their memory resources well and that suggests other major issues in their group. Just reads a bit amateur to me. No engine will save you from bad practices. The game builds are 64 bit, and the Editor will be also in Unity 5 (how did he not know this?).
It is notable that the guy is fascinated with a lot of things in UE4 that, as it turns out, you can also do as well or even better in Unity. He loves, for instance, Blueprint visual scripting... did he bother to check out uScript for Unity? He loves the node-based Shader in UE4.... well there is ShaderForge in Unity. He loves Physically Based Rendering in UE4 but doesn't mention Alloy in Unity. Sure some of these things are add on costs (usually pretty tiny) and there are also lower cost or sometimes even free alternatives to many of them. The best part is you can mix and match which pieces work best for you. If you don't like UE4's node-based shader... tough! But in Unity you have a few to pick form..... .... or better yet, you can make your own! The best part of Unity is how seamlessly extensible the editor is. This is a huge productivity booster. Every game we do we create custom tools that enhance the efficiency of the designers and artists. It's so easy to do, you just naturally create augmenting tools as the need comes up. Our designers and artists can do amazing things without ever having worry about writing any code... much less even a visual scripting system. This is because we made the tools specific to the game that let them express what they need all from the inspectors and the scene tools.
Another cool thing: make a great addon that is generally useful... then wrap it up and sell it in the Asset Store. Monetize that sucker! Or give it away for free if you like.
Is Unity perfect? Nope. But it is insanely efficient for developing games. Works with any sized team well enough, and creates titles that run across tons of platforms. And the Asset Store is a treasure trove of extensions that just make it better and better all the time.
The places where it falls behind a tad are either addresseable from add ons, and ultimately in Unity 5.
I am not advocating that one choose Unity over UE4... but if you are going to make an argument, at least make a balanced one with all the facts. I would take his critique with a grain of salt. Try each engine yourself, but make sure you take the time to fully understand both the tool and its eco-system and how it applies to what you are doing. And above all, make sure you have sharp developers on your team who understand the fundamentals. Like I said, no tool will get you out of a jam of your own making.