One slight concern I've been running into recently is the memory usage of ghc-modi. I've been on a rampage over the last few days trying to keep the Chart library from OOMing on my laptop, and this generally involves killing one or more ghc-modi instances with 1GB+ of resident memory. If anyone else can confirm this is an issue (and it isn't already a known issue/necessary evil), I'd be happy to file an issue on Github and do some preliminary work as to why this is happening.