I would much rather have a laptop that can get through a full 16 hour day when necessary than one that was twice as fast.
Study after study have shown that screen real estate and system performance improve our work output, let us use more of our working memory for task-critical state, etc.
If you need portability, then sure, laptops are necessary trade-off so that you can get any work done at all. However, that's all they are: a trade-off.
It's a shame if we're only optimizing for use cases that are ultimately regressive.
The only thing that comes close right now is a Thinkpad P70. Can get it with 64GB ECC RAM, Xeon E3-1505m, 4K 17" screen, 2 SSDs + 1 HDD, and a Quadro M5000M. The only problem is that it can't run OSX in some supported fashion, and the battery life likely isn't great. Sad that Apple has been falling short in the professional market for a while now and they expect everyone to be happy with thinner & lighter.
If your project has tendrils into the local system, that's the real problem to fix, because it's going to introduce pointless inefficiency at every level: new developer setup, production deployment, support for enterprise-installation, and ... inability to use the ideal hardware. available.
Performance translates directly into working efficiency. There's no such thing as "fast enough", there's only "too expensive".