We like to do our own cross-platform smartphone tests where possible, but since there's zero chance of an iPhone 5S and LG G2 being in the same room at the same time at All About Towers, I'd like to direct your attention to an excellent three way comparison over at GSM Arena, linked and quoted below. Perhaps not surprisingly, there was no overall winner, with the excellence of each and the differences in the software platforms ensuring that common sense prevailed in the end.

Setting the tone for the feature is this snippet from the verdict:

Are these the top three phones you can get? Well they certainly are in the running, but that's not the point here. It was a panorama instead of the best the three smartphone platforms have to offer. Luckily for the three - Apple iPhone 5s, LG G2 and Nokia Lumia 1020 - they are so different that they are not really in direct competition for the same buyers. 

While this is something of a cop out for a twelve page, detailed head to head (I'd have introduced some sort of scoring as I went along, if only for fun), I do appreciate the common sense being used here - it's unlikely that an iOS fan will consider an Android or Windows Phone device, for example. Ditto someone embroiled in Google and Android, they'll ignore the iPhone and Windows Phone. Where things get interesting though, is for the newcomer to smartphones - they'll encounter a seemingly level playing field and a rough scoring system might have helped them here.

Here are some salient quotes and constructive criticism from GSM Arena's final summary:

The Nokia Lumia 1020 dominated in still photography and did very well in video recording. Nokia's focus on proprietary camera lens apps also makes sure you'll be getting fun new options with the 1020 camera.

We probably could live with the hump but the slow shot to shot time (up to 4sec) is a deal-breaker by our books. And camera aside, you have to make a few other sacrifices if you're going with the Lumia 1020. The relatively large and thick body, coupled with a small battery is the first.

Software doesn't help either - Windows Phone 8 still hasn't matured as a platform even after the Amber update. It's not even 3 years old, iOS has been around for nearly twice as long and Apple is adding new features every year and polishing old ones.

The OS also holds back the hardware - you can't have a 1080p screen because of Windows Phone (which means no 5" screens with proper pixel density) and you can't have a powerful chipset. That makes a difference for gaming (a major section of any app store) and even with a custom chip Nokia couldn't get the shot-to-shot time of the camera to acceptable levels. The GDR3 update might fix all that, but it may be too late for the Lumia 1020.

The 4 second shot to shot time is only for Nokia Pro Camera, of course. Smart Camera, also included, shoots genuine burst photos, very fast indeed. I'll be examining any quality impact of switching to a different application in an upcoming feature.

I'd disagree about screens, size and speed. The 1020 is already on the large side of what most people will consider for a phone - there's no real need for a 5" monster at 1080p when a 768p 4.5" display does the job admirably in a genuinely pocketable device. And I've never once noticed the processor as a bottle neck when playing games on the flagship Windows Phones.....

You can start reading the full three-way comparison here, if you have the time.