Found this looking for an answer to a similar question. So, my 2800.com just broke. Laser went out of alignment (no drops or anything either, happened on a battery change). Leica support said they would replace it with a new unit for free within 2 weeks... Fast forward a month+, I get a call from Leica that they want $599 for a new unit, or will replace with a refurbished model for free but they have no idea when they will have one to send me... Long story short, Leica's warranty is not as advertised nor are their units as dependable as everyone says. Thus im looking for a new rangefinder considering the Razor or Sig.
On my reading thus far, seems like the Razor HD 4000 GB won't interface directly with the Kestrel, must chain to the GeoBallistics app with a phone. Only the 3500.com can interface directly with Kestrel. Sig 5K will interface directly w/Kestrel too, but not waterproof and warranty sucks.
I'm leaning toward plain jane Razor HD 4000 and inputting manually at this point. Dont want to spend Terrapin money, but need a unit that is actually going to hold up. What did you end up finding out?