Is 20 plenty, or is the new speed limit a step backwards for Wales?

The Welshpool area has woken up to a new 20mph default speed limit through its towns and villages.
The Welsh Government claims it will save lives and make us more environmentally friendly, but critics say it is a £32 million wasted exercise that will also damage the economy.
MyWelshpoolTV got the local angle...

[@chrismurphy7105]

I'm still confused as to how driving slower is better for the "environment", where's the science.

[@weebolddavy]

The day we got this government leaflet, 10 days ago, I was at my keep fit class and as normal we go to the leisure centre café afterwards for a coffee and I brought up the subject of the almost total abolition of the 30mph limit in Wales (if the leaflet is to believed).
Out of the 6 of us at the table, I was the only one who'd heard anything about it, so where they got the 63% of Welsh people agree with the lower speed limit figure from is anyone's guess, and the average journey in Wales will take 1 minute longer!
Did someone actually get paid to write those lies?
We don't all live in Cardiff and don't have the associated problems with traffic, collisions and injuries. What may work for cities may not be appropriate for the whole country. One size doesn't fit all.
Of the 22,000 miles of roads in Wales, 7,700 miles are now 20mph. I have no objection to driving at 20mph on residential roads, what I do object to is sitting at 20mph on roads when that speed is inappropriate and there are plenty of them.
We're going to have the situation where traffic is streaming towards a town at 50/60mph then it's down to 20mph which leads to traffic tailing back nose to tail and having the situation where there are no gaps for pedestrians to safely cross the road or for cars to come out of side streets and heaven forbid, turn right! Then the traffic catches up on a cyclist doing 10/12mph and cannot safely pass because of oncoming traffic, the traffic slows to that speed, then other cyclists may overtake or undertake the slow moving traffic. It's going to create danger in places where it didn't previously exist.
Another thing, the speed limit does not apply to cyclists as they're not mentioned in the Highway Code and cannot be prosecuted for speeding.
If they really want to save the NHS money from treating victims of traffic accidents wouldn't it be cheaper and fairer to lower the drink drive limit to what it is in Scotland and most of Europe and tackle the scourge of drug driving, these cause more serious accidents than speeding at 22mph? Between this and the proposed 'Tourist Tax' they would be as well closing off the border. As a member of the countries biggest motorhome forum which has over 60,000 members, they've been discussing these changes for months and almost unanimously decided to boycott Wales as the journey times in parts of Wales are already longer than anywhere else in the UK. It's any ones guess what businesses think of all this?
This has been yet another crazy idea to come out of this governments warped thinking. For a government which has been in power for 20 years, Wales should have moved forward not dragged ever closer to the Dark Ages. As they say 'Twenty is Plenty' it's time to get rid, enough is enough!

[@MyWelshpoolTV]

Some very interesting comments - particularly about the motorhome association.