Jan K.
Read terms and conditions first
Price/performance ratio is good, but be sure to read terms and conditions before using the service. Spent credits are non-refundable. It's probably a good idea to set some checks in place before running expensive intances. I have been using VastAI mostly to train neural networks for a chess engine. There were often drawbacks (machines not starting, ssh certificate or internet connectivity issues), but considering the hourly price for "unverified" machines, it was worth the trial and error. My worst experience took place I was charged for what effectively were "services not provided". I started a verified VM instance, which then was running for almost a day. Checking the progress on the next day, I found that the instance was turned offline without any warning somewhere along the way, meaning that I cannot access my data. The time the instance was online was fully charged to my account. I tried to resolve the issue with the support, but basically I was told that the charged time is not refundable. My losses were low, but good luck telling that someone running a H100 or better for a week.