Summoner Spells

So I've been wondering since the teleport change if it is still worth taking it since before I used to use it to go to side lanes while playing mid to get kills but now the delay is too long even if you want to split push the enemy can punish you way harder. I watched an lcs game the other day and from what i see is that the mid laners are going mostly ghost and flash I saw this on vlad and malz i know its viable on vlad but malz ? so should we be going ghost on diana I play a fair amount of twisted fate games and i always go ghost which really seems to help when I want to land my gold card when going in for a gank without using my ult. Also in matchups like annie and veigar is it worth taking cleanse ? since u can bait their stun and all in them or would it just be useless because they would have already finished their combo. Also ignite/flash still has the highest win rate on some sites so im really confused which summoner i should go now :p i usually go tele