Well, ordered the Alpine's at 5pm and miraculously they arrived 9am the following morning.... doesn't happen often !!
Anyway, just been testing them and used the highest (quiet) setting on the Alpine's in one ear, and then used a Howard Leight Max in the other ear just for comparison.
The Alpines have a lower NNR/SNR rating anyway even on the higher setting, so no problem hearing the engine or traffic just rather lower volume. The Howard Leights definately more numbing in that respect, to the degree you can hear youself breathing a little too much as well. Comparison not entirely fair with different ratings, but I would have to say I prefer the Alpine's.
Other differences:
> Alpines more comfortable when in place.
> Howard Leight's much easier to remove.
The Alpine's sit deeper in the ear so are a little more fiddly to get out. I guess it helps with isolating them from contact with the helmet but still fiddly to get out.
I will be using the Alpines from now on.... are they worth £16 ? Well yes if you have the cash to spare, I guess it depends how long they last of course.