Only some people from nicosia got the trial but you can find some answers here:
http://www.mivision.cyta.com.cy/english/index.php
They have several channels like BBC world and National Geographic. If those channels repeat some programs (they do sometimes) it is up to them and it does not depend on mivision. But since those channels are 24 hours a day i think it is ok if they repeat sometimes.
The how much it cost you can find in the above site: 25 pounds or 12 pounds if you already have i-choice.
If it worths it depends on who you are (how much you watch TV ...), how much 25 pounds worth for you and how much competitive packages cost.
Competitive packages can be from satellite providers, like Nova from Greece:
http://www.nova.gr/greek/ , I think you can get it in Cyprus also, but I don't know how much it costs.
Of course mivison has the added bonus that you can choose movies (but you have to pay for each one of them), and that you get basic internet with it.