Thank you very much for the insightful comment.
I tried out your recommendations, and tweaked them a little bit and I loved the outcome.
As a result, I have updated my guide once again.

Da what!!! are u high??? Twitch is a power hero when played right, Yes a good Vision Ward can be annoying but a good twitch player knows

1. The range of the ward
2. Where you have placed it
3. Can be countered by vision wards of their own or an Oracle's Elixir (preferably bought by an ally)
4. Can be counterd with Spray and Pray... Yes its true, try it! vision isnt everything!
5. You can change lanes
6. They just made you waiste cash

Now im sure your gonna say what about Oracle's Elixir... and i say sure put a big bloody target on your head and my team will take you out! waiste the 400 if u wish. I still have bushes, and hey being stealthed isnt the only reason for Ambush so chance my play style and your still gonna die!

That said: Most people dont know how to play twitch and thus give us rat's a bad name!

Now i have had my rant on the stilly comment! let me get onto the review of this guide!

Review
Good use of items and i can understand why you would want to have an Executioner's Calling, the crit is good, and the DOT will add in early game so you will do more damage if they escape. The active on it though is really only good versus people that heal ie Soraka. Might need to take into account other hero's though and consider replacing this depending on the situation with a Sword of the Divine (vs jax/teemo) or early Zeal or even remove it if you are versing a tankier team.

One of the biggest fallout's i see is vs high HP teams. Yes crit is nice and can do some nice damage but you really cant pass up a Madred's Bloodrazor to take them out.

As for the use of an Atma's Impaler i really dont see the benifit, i know it has some crit and armor but there are a lot better items out there for twitch if you need crit or if you are desperate for survivability. The 2% bonus to damage vs hp is just way to small unless your stacking hp items and if you are.... WTF are you doing! i ought to slap you along side the head with a smelly fish!

Cloak and Dagger is a great situational item and i would probably suggest moving it there. If you are getting surpressed or hit by a lot of CC then yes you may need it, but ask yourself why am i getting hit, what am i doing wrong???? that said attackspeed and crit is nice from it but you can get more from a second Phantom Dancer if thats what you require plus this will eliviate some more of your movement problems.

Hope this helps a bit, good work on your guide so far and keep building it :P

You might wanna look at expanding the item option sections and a little on gameplay, but your general gist is great

You know why Twitch is underused, right?

Because he sucks. No offense, it's just the champion. He's just like Evelynn, get a Vision Ward and BAM, he's dead. Riot really needs to rework him.

Well it was still in early production so it was actually removed from my preferred build. I played a game today with a Cloak and Dagger and as a result changed up a my build a bit

I am not saying it isn't worth getting, just that it is more effective in conjunction with other items. second, I don't think that word means what you think it means. I did not ask a question, I simply stated that I didn't think atma's was worth getting with your typical item build. =P

Hmm, this is just the build that I started with. I will definately revise it as time go by, and I will take your suggestions into consideration. And with your Atma's Impaler conundrum, I like it because of that critical chance it gives as well as the armor. I see it as a bonus is gives the AD too, so essentially I still see it as worthwhile

please note that multiple Avarice Blades do not stack. You will have increased gold gen. from one, but not from both. If you want to have 2 gold gen items, I would suggest grabbing a Heart of Gold, because that will give you more survivability.
Also, I would say that without any hp items, Atma's Impaler isn't worth the cost. It is only granting about 40 AD, and trace amounts of armor and crit. I would suggest not grabbing it unless you are grabbing Frozen Mallet.