I remember this discussion with numbnuts and using GT85 on chains and while i accept his experience....personally i wouldnt.
For me its too similar to WD40...and thats a definate no no for chains....but if it works for numbnuts, who am i to argue, i've never tried it. Its one of those things you shy away from, without really knowing why (talking about myself here)
For chains, i have my own method, but Mickles method is probably the most comprehensive and best method for chains IF you are happy using ordinary oil (engine oil etc) and an oil can. No need for removing chains, cheap, simple and relatively cheap compared to using Finish Line etc. If you like the idea of spending a bit more, Finish Line's range (and others) are good.
TBh, there's not a lot more you really really need to do lubrication wise in the summer. I do spray my calipers / derailleurs etc with WD once in a while, but its more for cleaning and very light lubrication than anything else, then wipe clean and dry with an old cloth.