Keep in mind, this forum is a place for issues. If there are a few bad cases out of a million, you will see that a few here. That's natural, if they find issues, first thing they do would be come here for help.
Point being, if you hear issues, like heating, battery life, you hear more bad things more quickly. That doesn't mean it is common. Generally speaking, those things are like the chances you won't get home every evening.
What the heck. You know you're going to buy it so just go buy it. You can return it if you don't like it. I've bought the RT, Surface 1, Surface Pro 2, & the Surface Pro 3 and have been happy with all of them. I still have all of them. Two pretty much gathering dust now. I guess I should find a happy home for them.
I'm not trying to waste your time. I should clarify that I had the i5 for a week but took it back both because I knew I would need a bigger disk bad because it was really buggy and noisy with the fan. I am hoping those were teething problems resolved via firmware updates but have seen enough complaints to give me second thoughts about the i7/512.
But if it mostly gamers and video editors having trouble then maybe I will be okay. Thank you.
You mentioned "intensive calculation programs". If those programs require high CPU usage for more than a few minutes, you will run into the same throttling issues as the video editors and gamers. Any sustained high CPU usage will invoke the aggressive throttling.
Also, the i7 really offers no practical advantage over the i5 due to the poor thermal design.
Do you have to listen real close, like putting your ear up close to the Surface to hear the fan when it comes on. I've never heard a fan come on on any of my Surfaces. I didn't hear it on my SP3 i7 even while running the Intel Extreme Tuning Utility CPU Stress Test. Sure my CPU or SSD gets hot in the upper right hand corner but if the fan comes on, it must be pretty quiet.