After a year they will terminate contract and you will probably reach ROI only.
Best alternative is - buy yourself mining equipment and start mining, you will reach ROI in couple of months and the rest will be profit.
You reach ROI sooner than 1 year. In 2-3 months (depending of course of how much you invest), you break even
Solo mining has no sense unless you live in a Country with "0" cost for electricity
Will have to see, as I am not mining with them long enough so far, but even adding maintanance (which isn‘t part of the forecast on the dashboard!) and calculating some decrease due to increasing difficulty, my forecasts all give a 2-3 months ROI like you said. And honestly: as long as it is below 6 months it will make you money and even allow to invest in a next years contract. Of course it‘s not like printing dollar bills anymore. If you expect this ... you will be disappointed.