It can be changed at any time, but if you change it during combat it won't affect that fight.

Pyro is certainly stronger. By a lot. But the changes currently on the PTS will make arsenal on similar level to other ranged classes, but pyro will still be ahead (but Pyro is very strong right now, so it's as it should be). So when 2.7 launches arsenal is kinda viable, and stronger than pyro on fights with lots of target switching. Best is to leran both pyro and arsenal and respec accordingly.

In addition to what everyone else is saying, why don't you join a guild that is aiming for the content you want to be doing?

There were a few slight buffs, but the main change is that people started experimenting and pushing the spec a lot more than before. I suppose the main reason people started pushing it was due to a bug that caused rail shot to vent heat twice for mercenaries, making the spec completely busted. And once that was fixed, people found that the lack of randomness was still a very good thing and managed to push the spec further and further. As for guides, odawgg's guide is indeed excellent. I also like my own of course (in my signature). They basically talk about the same things, just differently structured.

PvE. Pyrotech is the highest parsing sustained damage spec in the game right now (together with concealment operatives maybe). So while a bit lackluster in PvP, any changes they receive will have to not increase their damage output (and possibly even lower it a bit).

These Arsenal changes are a fair bit better than I would have dared to hope for. Free Rail Shot AND 100% proc chance on TM. It's going to be real interesting to try specing arsenal again.

You use the "by time" controls underneath all the fights. Set the first one to the same start time as the actual fight, and the other one to a second after what torparse suggests. That way you'll include the killshot as well. Like this: http://www.torparse.com/a/573669/time/1391269850/1391270105/0/Overview

So you're saying TD-> PSx2 -> RS -> Unload -> PS -> RS -> IM -> PSx2 -> Unload -> PS-> RS? Or just TD block-> IM block -> Unload block? I've been doing the latter basically all the time and still run out of heat easily. I could see the first one being heat neutral though. Edit: looking through the logs, it seems like it's indeed the former.

It has to do with the timing of the PPA proc. We're not 100% sure how the proc works, but what I've seen is that if you do your second power shot before the 6 second mark you won't get the proc, thus delaying rail shot. So with more alacrity, your attack cycle will take less time and thus you'll miss the proc more often. Due to latency and lag you'll still not miss the proc every time, but when I was specced into the alacrity talent on tier 1, I had a noticeable difference in regards to the PPA proc.

Pyro can cleanse just as well as arsenal can. I play a merc and have two of them in my raid team. Arsenal is slightly more bursty, but over 10 seconds or so, pyro catches up. And you lose more than some dps, you lose something in the vicinity of 10-15%. Arsenal is better on fights with lot of target switching (Draxus, Maybe Corruptor Zero), but that's it. If you have no other source of armor debuff then that's fine, but if we're talking about an optimized team you don't want an arsenal merc in it currently.

You don't want an arsenal merc in your group. If you're bringing mercs, and have no other option, then you force the sniper to put out the debuff. mercs lose much, much more dps by specing arsenal than snipers do from applying said debuff.

What he's asking is if teh targets affected by Missile Blasts splash damage also get the CCG DoT on, to which the answer is no. The corresponding talent for powertechs gives the ability to proc CCG to Flame Sweep which is an AoE attack. so with that all targets affect get the DoT. With Missile Blast, only the primary target gets it, reducing the specs AoE capabilities a bit in comparison.

In all honesty, they should just change both PPA and Barrage to work the same way they're going to change the Jugg Ravage proc. Use power shot/tracer missile gets you a buff, use them when having the buff gives you the proc.

That's a thread I missed, or had forgotten about. One thing did change between then and now though, there was a bug on railshot making it vent twice as much heat for mercenaries. While that's been fixed, that bug got a lot of players trying pyro. And when it was fixed, it still remained obvious that pyro was a stronger choice than arsenal, since even without the armor debuff, pyro was producing higher numbers. The nw dummy has just widened the gap.

This isn't true for healers. Both mercenaries and operatives have talents that increse surge by a lot, so they do want crit. How much is up for debate, but certainly more than 0. Also crit has no soft cap at 300, the diminishing retursn on crit are fairly low.