Frederick,
It depends on how much accuracy you want. There is a human element involved. If the difference between 12.2 and 12.5 matters to you then you might need to worry........ If you use the pyth function, you have to be sure you are at a 90 degree angle of the first wall and shoot the corner, then you have to be careful that you swivel the disto without moving it any direction and aim it at the other corner. .... I bought a desk tripod to help me swivel without moving, but trying not to move the base position and hitting the next corner can be tricky............ I will still argue it is quicker to argue a straight line wall with a tape measure. Many times there is nothing to aim at. Plus, you will find that pressing the "shoot" button will cause you to jump off your target from time to time. I am going to look into getting the red glasses. Total cost so far is near $700.
Tim and Fred,
I have to agree with Tim in regards to the Grandpa hands and the ability to see the dot in sunlight. After a couple cups of coffee in the morning that dot is all over the place. I put my Disto on an old camera Tripod. I use it with one leg extended and it keeps the Disto nice and steady, provides a good pivot for Pyth functions, and measuring second story stuff. Make sure your measuring reference is set to measure form the camera mount and not from the back of the Disto. That gives you a perfect pivot point.
I checked the accuracy of the Pyth on the second floor of my house on a 35-foot wall. Using the Tripod as a base I was able to come within a 1/5 inch. That's close enough for me. I tend to use the 3-point measuring technique, finding the minimun distance with the second measurement. This makes it easier to aim at the corners since you are making two shorter measurements.
Also, try using the delay function. After the laser is active press the "X" button once and it will give you a 10 second delay or hold for more time. This gives you time to aim the dot. After 10 seconds the Disto takes the measurement without having to press the button and move the dot.
I used the delay on my house as well. I have two perpendicular walls on my house that are at about 40 and 50 feet respectively. I set the Disto on the tripod at the corner, shot the beam parallel the first wall about six inches off pointing into open space, set the delay for 10 seconds, walked down to the end of the wall and held up my clipboard at the other corner until I could see the dot on it. When the dot disappears I know the measurement was triggered. Or listen close and you can hear the beep. Then I just rotated the Disto for the other wall and did the same thing. This was all in bright sun. By standing at the receiving end of the beam you can see the dot with no problem. I could have done the same thing with a tape by staking it at the corner but my house is new and there are no obstructions and I wasn't dragging the tape and having to roll it up. I think this will be useful in the winter when there is a foot of snow on the ground. If you have a helper, you could have him or her as the target holder.
I did a Condo this weekend and I was able to measure the entire place in under a minute. It can't be beat for internal measurements. It's nice for garages that are filled with junk too.
And finally, the red glasses I found are actually pretty low on the Geek Scale. They are not the goggle type and look like a pair of red safety glasses. Don't count on see me driving around town in them though.
Oh, And I got the "Classic".