We did the Coastal route in Sept-Oct 2019. Absolutely wonderful! Would do it again. No too crowded. Perfect weather for walking (around 17-20C), incredible scenery, a few hills. Would do it again.
You can see our little photo blog here...
This recent article sheds some science on trekking poles. It’s a roundup of scientific studies related to the use of poles over the last 40 years.
https://pubmed.ncbi.nlm.nih.gov/32980249/