I collect some statistic and do some math about current (after Staking Bonanza end) ORB staking for myself.
But think it may be interesting for other users to, so i post it here.
I collect 5 days of statistic from my own wallet with ~20k ORBs staking 24/7.
It is not new wallet - it staking few month already so all processes stabilize. I do not any manual corrections and allow wallet to manage all automatically.
And at current difficulty level (it fluctuate in range from 0.0075 to 0.012 while i collect statistic) i got this numbers:
average size of inputs in my wallet: 37.6 ORBs (initially i split inputs manual but later allow wallet do all splitting automatically so now it is random set of sizes from 25 to 50 ORBs, with average = 37.6 ORBs)
average time to generate PoS blocks for single input: 11.5 days (5 days to mature enough to start staking + 6.5 days of staking with continuously growing weight)
So with fixed PoS reward (1 ORB per block now) current interest rate: 1/37.6/11.5*100 = ~0.23% per day
Or
0.23%*365 = 84% annual interest rate (by simple % formula)
(1.0023^365-1)*100 = 131% annual interest rate (by complex % formula - if you reinvest all rewards generated and keep them all in wallet staking too)
Not bad at all even after Bonanza end!

Note 1: It is for 24/7 staking wallet with 24/7 Internet connection to ORB network. For example if you run only half day - you got only about half of interest too. (it is a big difference to classic PoS coins where no material stimulus to run wallets 24/7)
Note 2: while PoS reward is fixed in ORBs in % of interest rate it not fixed and highly depends on PoS difficulty(but not linear). Numbers above correct for current diff range (0.0075 - 0.012). If diff goes up (more miners begin staking or same miners add additional coins to staking wallets) % interest rate goes down. And vice versa. So it is nice self-balancing process here.