I got Rank 1 on Spirit Kings Heroic 25 two weeks in a rowgetting a rank in 25's is easier IF you have your raid "chose you" to receive all the time buffs they can, tricks of the trade -> with 5 rogues on rotation you can have this with a 100%~ uptime skull banners timed for Your cd's, letting you tunnel the boss while others deal with the rest etc. the sample size is about the same as for every 25 man raid there are 2-3 tanks 6-7 healers leaving 16 dps to compete against, in a 10 man it's 2 tank 2 healers leaving 6 to compete against ( if your going for top parse your guild is probably 2 healing it) so for every 25 there needs to be 2.666* 10 man's to have the same levels of competition. 10 v 25 also often skews certain specs in favour of one another -> more ads to deal with in 25 sometimes mean more aoe focused classes can shine more,
the only arguemnt i entertain in the 10v25 is that it's harder to get 25 people at the same quality level than you can get 10 and blizzard currently arn't rewarding the extra work it requires to get 25 isntead of 10 people of appropriate skill level.
it however annoys me no end when they do things like the dogs as they are imposibble to compare 10 v 25 as each week 10 gets a different level of difficulty but each week 25 is the same as even if each dog in 10 was "equal" to each other some of your radiers are always better at avoiding certain things that other or like mentioned Jade is unavoidable so it just a Healer thing and a "can make fucking up one of the other dogs klil you as jade made you not full HP"-> 25 has that Always jade only makes certain things kil you 3/4 weeks in 10 man it's every week as 25.
argument invalid
edit: without externals or special padding