Now, everybody already knows that a Zephyr is meant to stun>kill>hide kinda mech.   Zephyr had been one of my favorite mechs and I regularly run two of them.  Because of recent AI changes, life for a Zephyr has become a little more difficult because of it's low health.  Bots encountered at my pwr level (3250ish) have superuman aim and do not miss!  No amount of juking and sprinting will throw this off so you need to take cover.  Here are a few things I have made use of to maximize my kill efficiency and stay alive.

First, let's talk about ambushing.  Bots are still kinda stupid and you can take advantage of that.  When you are sitting in your ambush location and see a red target approaching, you need to identify whether the target is a human or a bot.  If it's a bot there are several things to watch for.  When bots are not engaged in combat or do not have a target in line of sight, their pathing is erratic.  Have your Zephyr positioned in a spot where a bot has to make pathing decisions.  Rotate you camera so you can watch the bot while still remaining out of sight.  Most of the time the bot will turn around briefly.  I don't know if the AI is have pathing issues or if the AI is having the bot searching for targets.  It doesn't matter though as this is the time to stun the sucker.  Even a Jugg with full shields will drop super quick when receiving double damage from the rear.

Human, players are a whole different matter.  You should know which way they are going based on the map.  You ambush location would ideally be a spot where they make a turn.  At this point you can stun and get a damage boost from a flanking position.  This only works if they do not know you are there so be sure to NOT MOVE.  If you stay still they can't see you on radar.

The other thing I would like to talk about is weapon choice.  Pretty much every Zephyr I encounter is loaded up with Missle Rack 8's.  This is a good choice, however, you really only get to take down one target very quickly and you do not get to take advantage of your stun time.  So it's stun, blast a mech, and hide.  Quite often you can stun multiple mechs but the MR8 really works for a single target.  Pulse cannons work OK for multiple targets if they are smaller mechs.  You definetely have enough ammo for two mechs if you can drop them within the stun timer which is highly unlikely.  Carbine 10/8 is pretty good but typically you run out of ammo on mech #2.  

Arc Torrent is definetely a problem solver with multple mechs.  This has nothing to do with it's ability to chain damage to other nearby mechs.  Very rarely do you get mechs piled on top of each other where the AT's super short range can hit multiple targets.  The key is in it's firing time.  It fires long enough to take down two or even three mechs.  Now, your probably thinking, "ya whatever, AT damage ain't that great".  It is if you combine it with a Thermal Lance 6.  When, the custom match was added, I started testing arc torrent damage versus other weapons such as MR8/MR8, Carbine 10/8, Stasis12/TL6.  I was about to request a dam refund of my AT10 purchase until I combined it with a thermal lance.  The damage is quite decent, even comparible to a carbine combo, however, the firing time is much longer than carbines which gives you the capabiity of taking down two, even, three mechs in a single stun.  Try it out. You'll be turning mechs into molten heaps no problem.