Mark Bridge writes:

I open the iPhone 6 box and discover a phone that feels substantial. Well engineered. Practical. Despite being just 6.9mm deep, it doesn't seem unreasonably delicate. In simple terms, handling the iPhone 6 is nowhere near as worrying as washing up wine glasses. In fact, during a week when a few iPhone users made headlines by complaining about the flexibility of their new handsets, I really couldn't see what the problem was.

If I had to grumble about anything, it would be that the restyled iPhone was less distinctive than its predecessors. Although there's no mistaking the Apple logo on the back, the original angular design has been softened with more curves, while the rear panel - once made from glass - is now metal with a couple of plastic inserts.

How did I get hold of this sleek new device?  Well, I'd been loaned a brand new iPhone 6 for a few days by Three UK. This in itself was intriguing. After all, you need to be pretty confident to do this kind of thing if you're promoting your own product. To put someone else's product on your network - and then invite a total stranger to give it a try - suggests an extraordinary level of confidence.

Anyway, into the box I delve. Handset, headphones, charging plug and USB cable. Yes, the phone uses Apple's proprietary 'lightning' connector, so I can't stick with my trusty microUSB lead. I mutter to myself for a few seconds.

There isn't a big manual in the box - frankly, there's no room - just a 'quick start' guide. "To start, turn on your iPhone by pressing and holding the Sleep/Wake button for a few seconds. Then follow the onscreen instructions to set up your iPhone."

I do, although it takes a couple of tries. It seems I wasn't holding or waiting long enough. First thing: connect to my home WiFi. What's this? The keyboard shows ALL CAPS all the time. I thought we'd moved on from the typewriter. Never mind. One of the joys of the new iOS 8 is that I can download another keyboard later.

Time to start exploring. I use the iPhone to log into my iTunes account and find a song I'd already bought via my PC. When I press 'play' the audio quality is surprisingly good, although it's only a mono speaker. Given Apple's music heritage with the iPod, I wonder when we'll see stereo speakers on an iPhone.

Incidentally, my own phone already plays its media in stereo. It's an HTC One; last year's M7 model rather than the newer M8, although I'd say it's still competing on the same playing field as the iPhone 6.

Let's move to the camera; something the HTC excels at. On the iPhone 6, the camera lens sticks out the back by a fraction (barely 1mm, I'd say). This is slightly disconcerting. It gives the impression of being a compromise in order to claim the sub-7mm depth, which feels a bit like cheating to me.

Still, I like the way it takes pictures. There's a little icon to warn you when the automatic flash is on, there's a time lapse mode for DIY cat videos and there's a self-portrait timer as well. Later, I look online to see some people getting very excited about the iPhone's 'selfie timer'. My own phone's been doing it for well over a year, although admittedly without offering a burst of images to choose from. A 'recently deleted' option even lets me recover deleted pictures that I later wish I'd kept. It's a good idea, although I can see it might result in an embarrassing outcome for some people.

Siri, Apple's voice-controlled virtual assistant, generally works well. It's natural and intuitive. This makes any failures - either misinterpretation or simply "I'm not sure I understand" - all the more disappointing. If ever sentient machines turn against mankind in a Terminator-like uprising, I'm sure they'll be led by Siri saying "no more weather forecasts, you puny humans".

Soon, I've added Twitter, Dropbox and Evernote apps, I've synchronised my Google contacts, calendar and email, and I've even installed the free SwiftKey keyboard app. (I have Swype on my Android phone but didn't want to spend 99p on an iOS version I wouldn't be keeping.) A friendly security-savvy email from Apple warns me that I've linked my ID to a new device.

After a few days, I realise that I'm getting on with the practicalities of the iPhone 6 rather nicely. That lightning connector is pretty convenient, as it can be inserted either way up for charging, unlike microUSB. Everything's running smoothly. Occasionally my lack of experience with iOS frustrates me - it takes a while to turn off those annoying noises in the Twitter app - but it's no worse than getting to know Android.

On the last day before I need to send the phone back to Three, I bump into a couple of my iPhone-owning friends. They're most impressed. They like the bigger screen and love the rounded edges. They'll definitely be upgrading their iPhone 4s and iPhone 5s to an iPhone 6 as soon as they can, so they tell me.

So, in summary, if you're in the market for a new Apple smartphone, this is likely to be everything you'd hoped for. And if you're looking more generally for a high-spec handset, the iPhone 6 - or its larger iPhone 6 Plus sibling - should definitely be one of the phones you consider. Personally, I was sad to say goodbye to my loan iPhone from Three. Still, I'm sure it'll be fine. It's tougher than it looks, you know.