You won't notice much of a difference with the accuracy Alpha boost. The endurance Alpha boost would let you run Tactics for even more chance to hit stuff than the accuracy Alpha boost. Give the recharge/healing one a try too. Alpha boosts are not locked in like enhancements, and they are relatively cheap for the first two tiers.
I dont know how much sense it really made, but I slotted Spirit Tree to get perma Soul Drain. Then went back to toggles and other powers and made sure to make them light on rech IO's and moved out a slot from hasten (after I do the math maybe 2). The heal helps, too as Syntax42 states. I also am expirementing from the muscular branch for the Radial Core bonuses (obiouly I dont have it but a lot of the bonuses seem to complement).
Miss Arc #147491: Rise of Bedlam
AKA Iron Smoke @Champion Server
Yeah, I've been running tactics and don't generally have a problem with dark consuption up so often and conserve power to fall back on if things go wrong, thanks for the replies folks, will likely try the recharge and damage ones if the accuracy isn't worth it. Thanks again 
The damage Alpha boost isn't worth it, in my opinion. At the second tier, 11% of it bypasses ED. You probably already have close to 100% damage bonus in most of your attacks and you get another 100% from Soul Drain. That puts you at 300% total damage for your attack. Going from 300% to about 315% only grants a 5% damage increase.
If you use the accuracy boost, look at your combat log. Fight some +4s and see if you have a 95% chance to hit without the accuracy boost. You probably will, especially with Tactics and Soul Drain up.
Just tried fighting some +4s and had a look at the logs, before soul drain it's around a 70-80% chance to hit and soul drain doesn't hit as much due to me slotting adjusted targetting to help get perma-hasten. Thanks for the feedback, will try and grab all 3 to swap between depending on the occassion 
My main, ma/sr, was kinda in a similiar position. He is perma hasten and the recharge wouldn't help too much. I know the stun duration would help on a Ma/, but most stuff is dead pretty quick.
After taking Mu mastery, and having a pretty aoe heavy attack chain at times, plus hasten end loss, I find I'm having end issues more than I did before I slotted into perma hasten and ball lighting.
I took the +dam and +end ones, and switch between the two as needed. If there is end relief on the team, I'll put the damage on. If the f/k doesn't use sb, ill put the +end one back in. Initially I was going to get them all just to have them available, but I think for now I'll jsut stock pile the shards for next issue. I really like the ability to switch them around when needed. I generally leave the +damage in. I guess from some of the above comments it might not be that much of an increase for you, but your a scrapper....and more damage is always good.
Hey, I'm just wondering what alpha slot gives the most useful values.