I've been looking at getting a new rangefinder. My current one, a Bushnell YP 800 has done an excellent job. It is just a bit big and a little dim. Now though, it seems every manufacturer is touting the need for horizontal distance calculations. I've never used a unit that could do that so; I'm left wondering just how much of an advantage such a feature offers. Do I really gain anything truly useful with this feature or would a simple, and less expensive line-of-sight rangefinder be sufficient?

Most of the time, as you say, it is not needed. The angle has to be fairly pronounced to make a large difference. Treestand hunters probably have the most need because of the height. Get one with a very good set of reviews, there are many opinions as to their dependability. If you are needing something for long range, spend some cash and get high quality with a good warranty. For mid range, it seems Bushnell is the one. Very good performance with less cost. For long range, Leica, Swaro, etc. are the way to go. For really long range, Vectronix or G7 are two of the ones to look at.
It really is dependent on your usage.

A buddy and I have the Bushnell 1000 and use them for ranging while rockchuck hunting. Available for less than $300. Mine works to 1100 yards on reflective surfaces.

if you hunt big game with a rifle and shoot inside 350 yrds there is no need for the actual horizontal, maybe in angles greater than 40 degrees. BUt a flat caliber rifle will eliminate your mistake (MPBR). Or if you bow hunt where knowing the distance is crucial, steep angles do come into play...

I shoot sheep at angles, but have learned to subtract some distance when shooting up or down at steep angles.rest of the time wind is the bigger factor.. dont worry about the rest, its just overcomplicating a shot. IMHO

MBPR?

I understand what you're saying here. That's why I can't decide if it's worth it to pay the extra on the horizontal compensation option. The difference in price for the model(s) I've been looking at is only $50 so; it's not a huge deal but, I still hate to spend even $50 on a feature that won't provide value.

Can anyone tell me for example:
On a 400 yd shot, if the angle is, say... 30*, how much would the "true ballistic range" actually be?

Since a 30* angle allows you to use the 3 - 4 - 5 formula you can figure it yourself. Hopefully someone will correct me, but I think it is 320 yards.

That much, huh? Well that's actually more significant than I would have thought. Hmmm. Maybe the angle compensation feature would be useful after all...

See if this helps you out lucznik. According to the table in the article, a 400 yard shot @ 30* would be equal to a 348 yd shot line of sight.

http://www.gundigest.com/shooting-articles-advice/playingtheangles

JG,

Fantastic signature line!