I just got a payout from ProHashing, so I looked at my ROI spreadsheet this morning. Currently my single L3+ from the May 5th batch is 42% ROI in Bitcoin terms and 99.5% ROI in dollar terms.
At the current difficulty (and not counting additional profitability from multi-pools), I'm about 80 days away from ROI in Bitcoin terms. That's the only number that's important to me. I always want my miners to produce more cryptocurrency than they cost.
On a semi-related note, I use Google Sheets to keep track of my mining and other Bitcoin investments because it provides a mechanism to automate the spreadsheets via simple scripting. My spreadsheets gather the received Bitcoin coming in to my mining addresses and include that revenue in the ROI calculation. Also, Google supports BTC to USD rate conversion. I had to add LTC, because they don't support it yet.
So when I check on ROI for my miners, pretty much all I have to do is open the spreadsheet in a browser and refresh it. Most of the time it works well. Every once in a while something gets "stuck" (probably some Google caching algorithm) and I have to make a meaningless edit in order to get it unstuck.
I have a forum post on this subject somewhere, but the scripts I used then are pretty old. If any one is interested, I'll start a GitHub project and post my latest scripts and instructions.
That is a great Idea. I would love to try it out... I get LTC payouts from Hashnest hopefully i can track those in my Google spreadsheets. as well.
Thanks