Upgrading from Samsung Galaxy S2 i9100 - recommendations?

[AC Question]

I have had this since 2011, just recently bought a new battery, but find it is running slower and the battery is going from 1/2 charge to empty, thinking its time to move on to a new phone.

Have loved this phone and think I would prefer to stick with android despite having an ipad, so looking for suggestions that are in the mid range, that would be a good upgrade.

Would love galaxy 7, but budget is about 1/3 the cost of one!