Is Bitmain antminer L3+ still profitable? I want to buy december batch but still not sure if it is worth it or there will be new one released soon?
no
Why do you say "no"? Even if you can make $15 a day after electric that is still a 4 month ROI, right?
Yes it is. The L3+ is a rock solid workhorse that draws relatively little watts and amps. You won't go wrong with them. Just manage your expectations. In the long run yes they are profitable and very user friendly. Best Scrypt miner out there IMO.