We have many, many people using GoDaddy as a host with GeneratePress. The actual GeneratePress theme is extremely simple and lightweight. The use of the add-ons definitely adds more features, but all of those features use core WordPress functions – there’s no bloat from other scripts or anything going on.
There’s also 0 PHP errors or warnings – everything is developed with WP_DEBUG turned on and PHP error reporting.
Efficiency is probably my number one priority when it comes to GP, I take it super seriously.
Theme-wise, GP uses 2 less database queries than the latest theme release from WordPress (Twenty Sixteen).
The biggest resource hog in the theme is the Google Fonts, and maybe Font Awesome. However, both of these are almost completely standard in all themes these days, and hardly take up any resources. You can also disable the use of both of these very easily (but you really shouldn’t have to).
I suggest installing the Query Monitor plugin to see where your resources are being spent. It may be a plugin or another issue.
Either way, thanks for trying GP – I hope you have better luck with the next theme you try 🙂