The 'like / dislike' proposal is an unwelcome one, and will (in my experience) lead to squabbles and bad feeling.
I use ADVFN and other Forum's where the use of 'like / dislike' generates reams of irrelevant posts, where people seek to find out who voted them down, and for what reason.
Some of these squabbles go on for ages, serve no purpose and create paranoia in some cases.
The other thing I have against it is that it gives the ability to 'slag off' someone's efforts anonymously.
This Forum has always been a good place for open debate, and even if it gets a little heated at times, we usually know who it is we are talking to.