We actually have built in a number of features at AskMrRobot.com over the last few weeks for the very purpose of taking these types of factors into account!

We added a save feature. This allows you to set up the site for your specific preferences such as content level, spirit cap, stat weights, etc. and then save it as a profile which can be loaded with one click when you come back.

Another feature is that we are now supporting and creating multiple stat weight presets. Check out blood dk's or bear druids for an example of how it works right now. This gives us the ability to collect default gearing strategies for multiple situations and provide them as easy one-click optimizations.

We would certainly like to hear from anyone who has good math for stat weights. Revising resto shaman stat weights is something I have been wanting to do - the defaults we have right now are decent, but we'd like to revise them to weight mastery more heavily based on some math I've been catching up on lately. Crit basically looks like a weak stat for resto shaman.

The site is completely user-customizable. The defaults are a convenience factor that we try our best to keep up to date for the majority of people who don't have time to search the web. Healing is subject to a high degree of personal preference and style, though, so we expect that users will want to customize to get what works for them.