Oh, I wasn't implying that Tomb Reaver always has 3 Sockets. One with a single socket can't really compare to either though, and two is, at the least, still less than three. =[
+Str equipment, you got me there. X) I've just always stuck to the ol' Shaftstop + Vamp Gaze for my Merc's armor so that never crossed my mind. The Bone Spear really doesn't do a whole lot though. 144-152 damage (Well according to the skill calculator, that's all the damage an unsynergized Lv16 BSpear does...) is going to slow monster regeneration at best. More damage is always better though, so I'm still not
complaining about it or anything. Low Level requirement lets you get it on your Merc by late NM too, which is pretty good.
Despite that lower average damage, the DS does help it out. Factoring in the fact your merc is going to hit for double damage as often as his Decrep fires off, the average total damage from your Merc is actually slightly higher than both Bonehew and Reaver. Decrep is just brilliant though.
Yeah, it can conflict with AD if you're going WWS or Atma's, but does that really matter? Decrep slows and weakens, plus you get some added damage anyway (not as much as AD, but still). The only time the confliction may be an issue is against Stone Skin monsters that AD can break the PI of and Decrep can't. It's the slowest in the bunch, but the enemies are attacking far, far slower as well. Even then it's barely slower than Bonehew.
A Bonehew socketed with 2x Amn still has less Leech than a 15% Toll AND will be slower if if use Toll's Socket for a Shael/IAS Jewel. That's not including the fact that Toll and Bonehew deal rather similar damage, not to mention the near-constant Decrepify will increase damage furthermore PLUS allow your merc to survive longer by weakening and slowing enemies. Overwriting Curses isn't really an issue since Decrep should be equally desireable as AD in almost all circumstances, perhaps even moreso. (This isn't the Necro forum, after all.) You could stick IAS into those Bonehew sockets to give a good speed advantage over the Toll, but then you're giving up your Leech and that won't help your Merc's survivability no matter how fast he attacks. =\
Bonehew is cool. Your Merc can use it before any of the others due to a low Level Req (get some +Str Gear [Andy's would be 8) ] or throw in a Hel) and by the time you hit Mid-60's the huge damage boost over whatever your merc was using before is just great. No wasting a Larzuk socketing quest either since the Sockets come built-in. But Toll is as good as Bonehew (or close enough) in the same areas as it is and has the added benefit of other things that Bonehew simply can't do (Decrep, for one). Your Merc won't need any Str-boosting items to equip it, either.
Bonehew is good, but Toll is just a wee bit better.
Even if you feel I overstated myself there... Tomb Reaver deals comparable damage to Bonehew, has far more IAS, and can come ready with as many or even more sockets. Even ignoring Tomb Reaver's other perks, it should be more undisputed than Toll that it's a better weapon than Bonehew is. Level Req or the huge expense gap may prevent your Merc in particular from using it, but either way Bonehew isn't on the top of the Three Amigos list (Bonehew, Reaper's Toll, Tomb Reaver) when it comes to Merc weapons.