Is the latest version of the Pentax 55-300 with ED glass and WR better than older versions

Can I have peoples opinion if it's worth upgrading this lens. I bought it when I had my K10D and now have a K3II. The Tamron 70-300 which I handed down to my daughter when I bought the 55-300 has given up the ghost and I am either considering a 2nd hand 55-300 or upgrading mine and doing another hand down.

The WR makes it worth an upgrade IMHO. If needing to replace I wouldn't hesitate in going for the HD version with WR, but we don't know yet whether or not the new collapsible version adds a new dimension to the situation. However, I wouldn't wait, we could wait forever and never get anything!

The latest version with the pulse motor is certainly a big improvement. A few from last fortnight in the Caribbean on my gallery here. Silent in operation, doesn't hunt, appears quicker to focus on my K3 and has electromagnetic stop down of aperture. I love it. F5.6 is at around 280mm which is an odd idea.

The 55-300 PLM is a great lenses. New optical design, collapsible, solid feel, improved af.