Buttery smooth, it's the quad core snapdragon with 1gb RAM & 8gb internal memory so thrown a 8gb SDHC in (32gb ordered) and transfer all the apps then uninstall all the crap, set up all my usual apps from the store i.e Whatsapp, Skype, Gmail, Messenger, Co Pilot, Electronics Wizard ect ect. Registered my win 10 hotmail account to it and it's like having the whole of my PC documents in my hand Onedrive is a top piece of software. It's so intuitive and fast too so win win all round. I used to add £10 a month in credit which was wasted for how much I used my old phone, so dropped to the £5 a month deals that Giffgaff do and got the handset for £4.75 a month for 24 month, boost the credit score and saved 25p each month.
Battery life is awesome too I charged it out the box 15:00 last Friday and it has just gone on charge 1:45 Monday, that's almost 59hrs on a 5 hour charge

and I've been giving it the beans tinkering and playing with it.