It looks cool.. I did it in my first house and as long as you have enough floor space it looks great... I would not do it in anything smaller then a 12x12 room though.. just looks to busy for some reason.
As for time... its not bad... the cutting is not the issues as much as lining up and fitting the thung and groove. Thats a bit more a hassle, but not bad. I did it in a 24x18 room and it looked awesome. I did a frame around the walls (about 8 inches) of just straight boards then diagonaled the main area.. Turned out great and didnt take much more time or hassle then laying it staight.
However, its all about the finsh.
