This calculator is awesome. It blows the other calculators out of the water. I use it all day now. Nobody else takes the time to add the new coins and that's where the highest yields are, so by the time you see it on whattomine everyone else is already mining it.
It's awesome but it's not consistent. Since a lot of these coins are small time or brand new they need to give an option to increase the average to say 3 or 5 days. It also needs a volume option. Without those picking a coin is a wash. Top coins on that list come and go in a flash, and often the top coins get there by very small trades of BTC. So if you have a decent amount of rigs you can't exactly just jump on the top coin without researching them to see if there's even enough trade volume and for how long.
Would also love an option to save the cards that are inputted. The competitor site lets you save all the cards that you put in just by keeping a pinned tab. Having to enter everything all the time is tedious.
Though if you have all these things planned of course, don't mind me, don't know how long the site has been around.