I have the Columbia Fast Trek II fleece and I bought the Helly Hansen for a change because my old one was too big. It's like day and night, unbelievable quality, much lighter, one of the main reasons to get a fleece in my opinion. And even though it seems more breathable, it keeps you just as warm. Personally, for Athens, if you're not riding a motorcycle, it's the only "jacket" you need

Very warm jacket, the only negative is that if you smoke, you have to be very careful because even a little ash will burn it directly!

Comfortable and lightweight jacket that you almost forget you're wearing. Despite that, and despite the fact that it is relatively thin, it is very warm, making it ideal for both autumn/spring with a t-shirt, as well as for winter, with something thicker naturally.
I should also note how quickly it dries after washing, which is important especially for winter with so much humidity in the atmosphere.

Very good quality and it is very lightweight. It has not been tested in cold weather yet (mainly used for winter hiking). The reasons for purchasing it are the very good reviews and its low weight and volume, which are very important for hiking.

Regarding the size, it is good to see it up close. The fit is slightly narrower than Columbia. With a Columbia shirt, medium is okay, but here, large was more okay so that it doesn't feel tight under the armpits, due to my broader shoulders (that's where I actually have difficulty). Nevertheless, the length is relatively okay (height 1.75m), it is understandable that the Large would be a bit long for me. The sleeves are slightly longer in medium and it doesn't have an elastic at the bottom to cinch it.

It is incredibly warm, tested on a day with zero degrees. Truly Polartec! And very lightweight, as if you're not wearing anything. Perhaps the only negative is that it has a straight line and there is no elastic at the bottom to make it close, so it could be even warmer

Excellent for intermediate layer and at quite low temperatures (tested near -10) despite being quite thin.

To be precise, I would give it four and a half stars for some details. Good, quality, soft, lightweight, hundred percent Polartec fleece, suitable for all seasons except very cold weather. I bought it at a very good price of 42 euros, which I think is unbeatable in the Greek market for Polartec fleece full zip. Nice fitted cut and a lovely khaki color.
On the slightly negative side for me, which are not prohibitive for me to buy it again, are the following.
The sleeves are a bit longer than they should be.
The lack of cuffs on the sleeves to keep them in place when rolled up, which is partially compensated by the snug fit of the sleeves.
And finally, the windstopper fleece behind the zipper, which does not fully cover the zipper but only the approximately 12 centimeters of the upper part near the neck, and when it is open, it looks somewhat unattractive.

It is perfect in the cold, although what came with the jacket I bought, despite being the same model, does NOT have the same materials of construction. Thinner but seems to do the same job. Time will tell.