From the article linked in the OP I don't think the lady has any mechanical knowledge or a clue what is under the bonnet. She obviously does not know how to access the 100 BHP which is more than adequate for a small car if she needs it. As for no interlock on reverse, she can't have tried to get reverse from anywhere but neutral. There are a few reviews around where the writer does not realise that the Jazz is a two mode car, normal pottering about, and i-vetc when power is required. As for uphill performance, my car will maintain 70 mph up the steepest motorway hill in the UK in 6th gear on cruise control (southbound M90 from Bridge of Earn which is outside the motorway maximum gradient spec but no option due to terrain) although the change down light comes on near the top.
My son in law had a S2000, that had awesome vetc, my daughter ordered its sale after a couple of damp road spins. :-)