Well, that's a tough call. What do you want? PVE or PVP? I would warn you that without a speed reload perk (outlaw, spray and play) the TL takes a LONG time to reload. Here are the perks you can get with a description. http://www.destinydb.com/items/2266591883-timurs-lash You can see what perks you would settle for and calculate the odds of getting something you like better by multiplying the fractions. 20 rolls might get you something better, but like any gambling, it's not a sure thing. If you got most of what you want, I would probably keep it. You could wind up with some bad combination of perks at the end.