(Details regarding the aforementioned prop-flying if you don't know:
by picking up a brick and putting it under a certain prop while crouching, uncrouching will make the prop elevate in the air, and the player with it. However the player is very limited, since he is forced to always look down and cannot switch weapons and must keep holding the stick to pick up props. Direction is hard to control, and it's very risky to try to land.)
Personally, I think it's not. Exploits offer some kind of advantage to the player. Using this, the player has the possibility to "fly" around the map, but the props being instable, it is very dangerous, and even an experienced player may die from falling quickly.
Important to note that the prop-flying doesn't allow the player to reach any unreachable areas, or even hard to reach. Also important, prop-flying does not make for a good escape vehicles or anything like that. The player in the air is an easy target, his movements are restricted, and he can only travel above regular roads, at the same speed as running players, if not slightly slower.
Finally, I have the feeling the mapper deliberatly added this into this map, as evidenced by: the two props needed being so close to each other; the map being apparently thought perfectly for the purpose of flying since like I said before, no unreachable area may be accessed.
Why it shouldn't be exploiting:
1) No advantage to the player whatsoever; in the contrary, it endangers the player greatly
2) Cannot be used to access any areas that would not be accessible otherwise: which in that case would really be exploting.
3) Possibility that the mapper intentionally added the glitch, judging by the previous sentence and the evidenced proximity between the two props needed.
Therefore, it should be tolerated that players use the glitch, which is to their own disadvantage and only for fun, may I repeat.
Edit: The above is for ttt_forest only. Prop-flying on ttt_rooftops is another story. Feel free to discuss ttt_rooftops below though.
Edited by Loadingue, 31 July 2013 - 13:55.