Regarding networks taking a big share i do have to say this: they will only take as much as you allow them.... if you willingly sign a contract with a 60/40 split then you have done it knowing what the end result would be when receiving a payment.
But nowadays it is so easy to to get better rev-share that taking a big cut does not apply here. Remember that in a way, who takes the biggest cut is google itself. The problem with the network share is that it is a cut that you actually see in your earnings, while google does on the background and you don't even realise the 45% they are taking from you, although the info is there, it is just something that ppl filter out, and somehow, they just focus on what the mcn takes.
Each network may or may not actively promote your channel, and promote may have different significate in each network.
Most networks will provide tools that enable the creator to develop their channel. Some will provide a one to one channel assessment to help the creator if possible (cough my case cough cough), create communities that ultimately are innefective because everyone there will be asking and few will be sharing and helping. Smaller networks will give you a better chance in getting promoted by them, by putting your videos on their hubs, social pages and so on, but because they are small so is their network. Big networks.... well. You won't be promoted, period. Unless you have a big channel, you may have a chance of being promoted on their hubs, sites, social media, and if this happens, yes! That will/may represent big exposure for your channel. But i will repeat.... You will need to have a very big channel.... or be incredibly lucky/persistent/voodoo expert/annoying as hell/have connections within..... But you will need to have this in your mind... big networks will promote big channels because they are doing it for their own interest, not the creators interest. It suites them showing off the big youtubers they have, because you know, big fish atracts bigger fish.
Personally, and if i wasn't in the business, i would still be partnered to a network, but i would go for a smaller mcn, probe their response times/support level and if possible talk with someone live other than just pure email.
Don't join a network because you hope to get promoted, join a network because of the perks it can give you, but specially and mainly because of the quality of support.
