CEN - Sigh. There is a misunderstanding of how/when SRB kicks in. While under active exploration /development, Thailand offers very competitive tax rates, which are better than Indonesia in almost every instance. Thailand's tax regime is excellent for juniors as it allows deductions for capex, which shields them from paying taxes when it is needed most (ie early in a field's life when capex is high and production/cashflow modest). Tax rates climb once development slows and fields mature and go into "harvest mode" - from my perspective from someone who invests exclusively in juniors, I find that sane taxation policy as it incentivizes companies to aggressively drill and develop while allowing fast return of risk capital.
MMT, until they renegotiated their operator status in 2011, was paying ~60% tax plus 8% royalty- significantly higher than CEN. (MMT now pays about 35% effective tax but royalties will rise to ~20% in the next year or two as production rises).
Those that think 50-60% is outrageous might be shocked to learn that effective tax/royalty rates in the UK/US are often very similar (particularly in sought-after plays like the Bakken/Eagle Ford etc where land owners demand fat royalties).
Anyone who is concerned about the effect of taxation in various companies operating in different countries merely needs to look at the 51-101 reserve reports which value reserves after all taxes/royalties are accounted for. So long as everyone compares apples to apples (ie look at similar reserves at similar oil prices), there shouldn't be confusion.