I'm bit behind, so will do my first impressions first, and then the challenges.
~ What handset did you have before and what frustrated you about it?
I had an HTC Desire C. Mostly, I liked it, but it struggled with some videos, and the screen shattered when I dropped it. It only had a camera facing away from me, so I couldn't take selfies, and the Cbeebies app didn't work on it. Also, I couldn't use it in the rain, and the screen was very hard to read in sunshine.
~ What was most appealing about the Samsung Galaxy S4 Active?
When I read the description, the ruggedness was the most appealing thing. I like to read in the bath, and being able to use my kindle app without worrying was a very attractive prospect.
~ What were your first impressions when it arrived and you got it fired up? How was the set up?
My first impression was that it was very sleek and pretty (I was expecting something a bit more butch looking) but also that it was huge compared to my old phone. It was bit annoying having to get my sim card cut down. I was also not entirely confident in the sturdiness of the hole for the charger - I worry that this will break within a year or so, and it does does make charging the phone a little more hassle. I have (TMI) a waterproof rechargeable vibrator which doesn't have any of the faffy cover but seems to work well anyway.
~ What features have you used so far? What's your opinion of these?
I really, really like this phone. Rather surprisingly, I'm finding the voice activation on the camera very useful, as the phone is a tiny bit too big to take pictures with one hand. I wasn't keen on the head-tilty thing which was a bit gimmicky and not really useful. I like the thing where you wave your hand over the locked screen and you can see the basic info. I like the swipey keyboard, and really like the way that it is big enough to have numbers on the top row, although it would be nice to have a simpler swipey way of getting the most common punctuation symbols. I like the bigger screen very much. I tried a video google hangout with DP, but the video quality wasn't really good enough to make it worthwhile. I love love love the screen sensitivity, and the ability to set it so that you can use normal gloves, and that it works in rain. I tried to set it up as a remote control, but my TV is too old to work with it, so I gave up.
~ What about how the phone looks and feels in your hand?
I love the look of it. It is sleek and shiny and beautiful, the screen is clear. the rivet-style buttons on the back spoil the sleekness a bit, so I'm not too keen on them. I do find the phone just a teeny too big for perfect ease of use - I have to stretch my hand really wide, and have to use two hands of lots of things that I used to use one hand for with my old, smaller phone. Also, it needs fairly big pockets, and it's too big to keep inside my bra if I'm wearing something without pockets, which means that the pedometer is less useful that it would be if it was securely in my pocket the whole time. The screen is abolutely lovely, though. I like the haptic feedback which is just right.
~ Any additional comments
I was very impressed with the general set-up of the phone - the settings menu is increbily user-friendly and easy to use. The battery life isn't great, but no worse than any other smartphone I've had. I find the various screens very easy to navigate. It works very well for listening to music, podcasts and watching youtube.