UKC

I am looking for a pair of hiking boots, mainly for hiking and trecking and mountain climbing below the snow line, with rare occasional stints above the snow line.

I saw rave review's about La Sportiva Nepal's and bought a pair but realised how rigid the soles are for ice climbing and think maybe they are not the best for my purposes.

Would such a rigid sole be uncomfortable when I will be hiking on relatively flat and maybe muddy terrain most of the time?

Would something like the scarpa sl active or meindl borneo be more appropriate for below the snowline hikes?

Meindl Borneo for my money.  They also have a leather lining and a very tough sole, unlike a lot of the competition. 

Walking in stiff soled boots like Nepals is a necessary evil, to be avoided if possible

You might also consider a pair of shoes, like the Scarpa Mescalito.

If you are walking and scrambling in mainly dry conditions you don't even need the weight of a leather boot.

La Sportiva Nepal's are excellent boots. I had them for many years, and I have just bought a new pair. These are heavy boots intended for mountaineering. Stiff sole for crampons and good ankle support. I am not an expert ice climber, but I climbed moderate icefalls in them.

That said they are overkill for hiking: heavy and too warm.

I am quite happy with Meindl Air Revolution 4.1 for trekking. You can use them with crampons, although ankle support is inferior compared to Nepal's. They were ok on an easy glacier.

They are light and comfortable. Last year I had them on a multiday trip with a heavy backpack (tent, camping equipment, food).   The only complaint from the trip: they are less watertight than heavier boots. On the other hand, the latter are less breathable, so you suffer on warm days. 

Well, about 10 years ago I was rather skint and couldn't justify buying a second pair of mountain boots so I spent about 18 months using my Nepals for just about everything.

In terms of scrambling in N Wales in glorious June sunshine they actually performed amazingly on the technical scrambling, they were just a bit heavy and rather too warm for the several hours of approach and descent either side.

Equally they were great in keeping my feet dry and warm crossing bogs and streams on big hill days although at the expense of being less suitable for longer and quicker walking on good paths and tracks.

It all probably comes down to how well they fit your feet. If they are a really comfortable fit, using them for a couple of days in Summer conditions won't be the end of the world. Probably not the best idea to try them out straight away on some big, committing backpacking trip but you won't lose much by giving them a go.

That said the Scarpa SL (or the Scarpa Delta - I'm on my second pair of them) are really great boots, assuming they fit you.