It seems like no one here has there head on straight when it comes to this, the real problem with it, and why it is nerfed, is that if you get it with skirmishers, you are simply too powerful. Someone said the only way to make good use of it is with poachers, and that is the way it is suppose to be. If you want infinite scaling damage on your auto attack, then you just need to accept that it comes with the price of not smiting champions, and that is fine, you don't need it. I get poacher/devourer on Yi, Xin, Shyvana, fiora, udyr, and gasp elise(who people think is bad), and i have no problems at all.
I'm going to go against what I believe in here, and provide my strat for it.
1.) You need to be good enough to know where the enemy jungler is going to start, and then start at the opposite side of his jungle.
example, if enemy jungler is starting blue side, I will start on his golems, then get his red, then his raptors, generally I will only use smite on his golems. then go to your own gromp, smite it for the buff, get your blue, after getting your blue, go straight to your red and smite kill it.
the objective here is that you are removing enough jungle xp from the map, that their jungler will get behind/frustrated, and commit to a gank with a low success chance, thus putting him further behind, and maybe even making him feed a lane. If he doesnt then he will have to steal xp from a laner to catch back up.
2.) You need to let your team know your intentions, so they know to be careful because you arent going to gank for a bit, because a feeding team will ruin this play style for you. Also, around the time that you are heading to your red buff, their jungler will be realizing what has happened. he will either go to your red and attempt to get the drop on you, or he will gank almost instantly. let your team know so that you can capitalize on this
- )WARD. Cant stress that enough. Not just your trinket ward. buy wards. If you like to use teleport, then they arent just for vision, you know have a handy spot where you can tp into the enemy jungle for your poachers but also, you need to back as soon as you have enough for poachers, as soon as you get the gold to upgrade your hunters machete, go back and get it. Pay attention to the timer on whatever jungle you stole from the enemy, odds are he will be off somewhere ganking instead of making sure he secures its second spawn, and you will get to clear it again, this time with bonus gold from poacher. continue to kill jungle camps, and make sure to back as soon as you have enough for devourer, so that you have maximum time to build stacks.
4.) Wits end is an incredibly underrated item, it doesnt matter if none of your skills are AP, 42 magic damage per hit totals up to alot when you already have a devourer. Plus the magic resist that you lower on enemy champs makes your devourer hit even harder, and the next item you should get is sunfire cape(sometimes i switch the order and get sunfire before wits end if they are all AD or something). Now if someone could kill you before, they sure cant now, you should be able to 1v1 anyone in a game with you at this point, unless they are doing exactly this right back to you, maybe even 1v2 if you are good/lucky. The rest of your items are variable depending on the champ, and I actually do something completely different on yi and fiora, so if you are trying to play them, ignore this
5.) Dont fall off. Once you have devourer, it is important that you dont gank too much, and also dont spend too much time in lanes, you no longer care about lane minions at this point. Make sure you are on point with getting jungle mobs to keep scaling up, because if you fall off, it is going to hurt.
Here is a link to me doing this(most of it) on yi. for anyone who would like to see it done.
http://www.twitch.tv/the_chronicler/b/649813534