shale gas v. csg

The ann that BHP has splashed Billions on a relatively small Shale-Gas deposit (that IS in production) has stirred interest in all things Shale! I'm not an expert on either Shale or CSG but here's my take:
1) Shale that has the right structure/chemistry can hold huge amounts of natural gas... far bigger than realised even 5 years ago.
2) Modern methods ensure the gas can be released in quantities that are not just commercial but highly profitable. The Chesapeake deposits in USA have surprised everyone with the size and flow of gas.
3)Shale gas is far less controverial than CSG. The latter has constant hum of environmental isssues especially as some occurs at fairly shallow depths in arable areas and near to artesian basin... Australia's most precious resource IMO (ahead of barrier Reef). I can't contemplate us allowing this unique basin to be contaminated.
4) However, some CSG is being produced sucessfully. Best example is Arrow Energy who have resource in Western Qld (Surat basin) far away from ploughed fields and irrigation. In addition the coal is relatively deep and extraction appears safe.
5) Oil from sand/shale in Canada has proven to be extremely expensive and energy intensive. This is not case with Shale-Gas or CSV.
6) Shale gas requires far less drilling. CSG wells are of shorter life and closer spaced as fracking methods are dissimilar.
7) CSG is methane. Natural gas has higher calorific value.
8) The Cooper basin already has network of pipelines for both gas and oil. Hence, connecting to existing infrastructure not requiring huge CAPEX.
9) BPT/ADE shale occurs in far wider seams that coal. 400m v. 4 metres!
10) BPT sold all their CSG assets to Arrow. But kept the shale. Is this the smart move?

As stated i am no expert and invite others to comment.
MM.