I chose differently, but here is how it went for me: I was lvl 34 at this point.

I have Razer Naga, so my keybinds are somewhat unimportant since they are all on my thumb. However, as for layout here it is in general, with specific binds in Spoilers to save space: Top Bar: DPS abilities that don't require cover, as well as "roll into cover" itself. Basically, I want everything I can use on the run, and what I need to get back into cover available to me. Cover Bar: All Cover abilities plus default attack. Damage, damage, and MOAR DMG! Bottom Bar: Stuns, Interrupts, Snares, Debuffs, Situational. It's my escapes and Oh ***** for the most part I skip button 6 since it is just easier for me to hit 7 than 6. Big thumbs. I still have a few abilities to pick up, so things will get rearranged by 50.

I have actually had this happen to Ambush too, but mostly snipe, and usually at the beginning of a fight after entering cover. I am wondering if there is a bug with one of Kaliyo's attacks that stops our casting. Several times I have been mid cast and seen her leap forward or attack and at the same time had my snipe cut off.

Sniper's Nest is a must have.

@Atharyia: Thanks for the link. From what I saw there was only a post about why a Lethality/Engineering hybrid was bad. Most of that was concerns about how it relies on expensive abilities (20+ energy), namely Cull. My build doesn't rely on expensive shots, actually makes the probes cheaper, and the regen from Cluster bombs, while possible not being able to get the full 15 back, is still a net reduction in energy costs. I think it will just take some testing when I get access to Series of SHots and Followthrough to see what kind of damage they are dishing out. @Zantral: The spec is for PVE purposes. If it was PVP I would definitely grab the 31 point talent for the nice burst of spamming Series of Shots 3 times. @Cruxified: There are always options within the trees, but it is usually survivability vs utility because you will always pick up damage buffs. For example do I reduce the cooldown on Leg Shot or go for Range Defense bonus on leaving cover. If you don't put dmg buffs in trees it means everything is strong baseline, which means every sniper plays the same essentially from a damage perspective. With damage buffs split between trees, Lethality plays different from Marksman which plays different from Engineering.

I know there has to be a number of you guys out there scheming on your lvl 50 specs. I have been toying around with the calculator a bit and have put together a couple interesting builds. However, since I didn't take a Sniper past lvl 25 in beta, I won't be able to weigh some of the top tier talents vs some of the options I could get in another tree. I've been toying with the build below, but I don't how the buffed explosive probe dmg, cluster bomb dmg and energy regen, and Interrogation probe dot would weigh against the bonus crit dmg and Series of Shots reset at the top of Marksmanship. I don't know what % of total overall DMG Followthrough and Series of Shots is at lvl 50, so as far as I know, the build could be complete crap because those top tier Marks talents are vital. http://www.torhead.com/skill-calc#400bsrdbMRRZrI0bRoZb.1 I would appreciate any knowledge you can share if you have played a lvl 50 Sniper in beta.