We recently stayed three nights at Carl's place and were very pleased we did.
As others have already mentioned it is very convenient- being an easy 10 minute (or less) walk to town and also to Pukekura Park.
It was very well set-up in all regards , with a good range of kitchen utensils to self-cater and a nice outdoor dining area.
The decor was modern with a nod to retro and industrial vintage style which definitely appealed to me.

For anyone visiting New Plymouth I would highly recommend Carl's as a place to stay, offering excellent value for money.