I think power wise for wired headphone use the older FiiO is good. I have used this,
New one looks better on features and wireless use. Depends on what is your use case you can choose.
I felt the fiioX3 1st generation more powerful than 2nd but 2nd was more refined. Alternatively you can look for cayin n3 or xduoo x20 which has lot of useful features and sounds very nice. if you can source anything from US, then get the hiby r3 which i had a chance to personally try and liked alot. it feels premium in hand.
I recently bought Fiio X7 Mark 2 and it really sounds good. Specially over the Bluetooth, i own B&W PX headphones which support aptxHD. The sound is really good, instrument separation, sound stage etc..Listening to entire music library once again..
I finally decided to give the Shanling M0 a try over the Fiio M7...pre-ordered it last week.... Hope to get it by this month end. What I saved was spent towards the Massdrop Sennheiser HD6XX which is a pretty sweet deal at $199. Only downside is I dont get the headphones till the end of Nov from the US when someone can bring them back.