After having spoken to a number of ADs in the UK,in Malaysia and in Singapore, I can conclude on the following:
The daily tolerance of the 5277 is +5 -1. The annual production of Breguet is currently a lot higher than the 5,000 pieces it used to produce pre Swatch group. In fact, unlike other brands, Breguet will not release information on the precise numbers but 20,000 is a likely figure.
Most Lange watches have a daily tolerance of +3 -2 (like Patek). The annual production for Lange is 5,000 pieces and they are therefore more exclusive. Their watches are assembled twice unlike other brands to ensure superb quality. Lange is fortunate to be based in Glashutte where wages are lower than in Switzerland or else their watches will be priced even more steeply because a Lange is still relatively good value compared to a Patek and a Vacheron. Each balance cock is hand engraved by one of only 6 engravers (each with his/her own style) making each watch unique.
Speaking to one of the best watchmakers or at least one of the best at finishing watches, Kari Voutilainen, he said that the finishing at Lange is amazing at the price they sell their watches for and apart his own brand, he would wear a Lange or a FP Journe.
Now I will admit that Breguet is at the forefront of watch technology with its use of silicon and the dials are intricate. I believe the Swatch group has adopted a more aggressive approach in their marketing of Breguet by opening many boutiques around the world and reducing the sale of their watches from normal retail outlets. They have also undercut their main rivals by pricing their watches much more favourably. Lucky us then, the collectors and connoisseurs who can now buy watches like the 5277 at under $20k or £13,600.
I have owned a Lange up and down but felt it was a bit large for me at 39mm. I have since sold it as it was not as slim as I am used to. The Breguet at 38mm is slimmer and lighter and to me much more wearable and I hope to purchase it one day. To wind up the Lange with its 72 hours of power reserve on a single barrel (instead of two or more barrels) took me more than 150 rotations which I found excessive. The Breguet with its 96 hour power reserve can be fully wound on fewer rotations (sorry I did not count but it was less than 100). If you look at the movement of both watches though, the quality of the Lange is more apparent than the Breguet.
The above is purely my observation and many of you I know will prefer larger and heavier watches while others may buy a watch which is more exclusive. For me the accuracy, dial, size,weight,history and slimness are all important factors.