I have all three legendary swords, and I haven't finished the exotic quests yet, but they haven't been a priority until recently. It took me about 2 or 3 hours per character to beat the TTK main story and get the sword, that's about 6 to 9 hours total to get all three swords. I transferred them all to my Hunter, and it has taken me weeks to get them all infused to 280+. The legendary Sword Reforged quest (the one where you get PvE and PvP sword kills and then kill the knight dude) took me the better part of a day off. I only had to complete that once and I got the exotic Sword Reforged quest for all three. Yesterday I spent about 4 hours farming the materials. With my Nightstalker's improved radar I was able to get all 10 Relic Crystals and 7 Soliton Flares, and 25% of the void ability kills.