You provided 2 tutorials for this: what's the difference between twitterfeed and feedburner?
No difference...
however
Twitterfeed:You can autopost to Twitter,Facebook,LinkedIN and two others..
You have selction of shorturl like bit.ly tinyurl for your Twitter and facebook updates.
you can have max 5 updates every 1/2 hour.
Feedburner:
Owned by Google, can be used using your gmail account.
Only offer posting to Twitter
Max autopost 8 post every 1/2 hour
Only one shorturl is offered goo.gl
More customization than twitterfeed.
Can be linked to adsense account.
you can just use twitterfeed or feedburner for twitter and twitterfeed for the rest..