IOS
- Closed, limited and premium all around (often without reason except forcing you to spend more)
- Abundance of good apps (at a price)
- Smooth and subject to frequent updates (with the UI never changing its childish looks anyways)
- UI is boring
- Once you go Apple all what you do must happen in Apple universe. Not good for people affected by claustrophobia.
- Relatively secure
- One single, unified platform (no fragmentation)
- Not enough customizable
Android
- "OPEN" (So to say)
- Abundance of apps (many of which are trash)
- Rarely smooth since day one. Tends to slow to unbearable levels after a while (startup is a nightmare on all my Androids after one year or so)
- Security and privacy with Google are like the Bigfoot...everyone talks about it but no one has ever seen it and when a picture shows...worry not...it's blurred. Android is the same. (3 recorded attempts to steal personal data from a third party keyboard, which is also a very good keyboard by the way; compass apps asking to see your SMS, photocamera apps asking to see your mom's bra size and so forth)
- Platform is fragmented. Support ends quick (based on country, operator, manufacturer look how many levels you have....) and you spent a good bunch of money to use a device that gets old in no time (my WP got 3 updates in less than one year.....it's true they add 1 function at a time and advertise it like the next big thing everyone else has had for a decade. Perhaps they fear they may run out of new functions so they add them once at a time....).
- Platform is completely integrated. Sharing is a breeze and sharing option add up as you install new apps (sharing to pocket/instapaper is everywhere, sharing to messaging clients of third parties is there and is a complete list in most apps
- Split screen in big screen devices really boosts productivity
- Choice of key apps allows everyone to create a phone that's cut for your needs.
- Customizations are deep and infinite (try something like Themer to understand what i mean). Widgets, background, icons etc. There is a genuine chance to create a device like no one. You manage to fit all what you need in one single home page if you really want
- Really good maps. You find what you need and distances and times are pretty much accurate. They take you to the place at least in my place.
WP
- A midway between Android and Apple in terms of openness (Windows Mobile was much better than them all and i know someone may find this statement daring).
- API are closed and limited (opening now) with devs reluctant to invest time and money in APIs that limit software potentialities. This reflects in market and app quality. Deep scarcity and quality of good apps is a key issue for WP.
- UI is very nice. However limitations in customization (colors first inline), make it boring after a while. This has been partly fixed in 8.1 but still doesn't feel right. Lack of three row tiles makes the biggest tiles look small on devices like 1520. Of course the 3 tiles may come as new function in 3 or 4 years.
- Lack of very basic functions (Keyboard inputs, complete sharing functions showing and adding automatically new apps that can share in browser, messaging clients, photo apps, proper multi mail account, Office not letting you edit files, and many other basic things that now escape my memory) it's all missing. Even file managers are terrible (In some you have to manually add the directories to be scanned...and they are sold at a price, too).
- Lack of real choice. Example is browsers. You can download them all and you notice them all have the same UI more or less, same functions (or lack thereof) etc. It's like a Soviet method where you make ten types of cars with different brands but they are all licensed by one single manufacturer and they all look the same....except for some details. This not only makes UIs boring. It also drags issues of original app onto all the others.
- Market is a show. You make a search for A and get 10 results for A and 200.000 for all other unrelated items you don't need. Two thousand apps carry the same or similar name, some even same icons in different sizes (Telegram messaging copies for example but there are tons of those, games in particular). 80% of what you find in the market is unusable for one reason or the other. I am amazed at how Microsoft allows this to happen. Setting language to one particular region (ex. China or Taiwan to mention a few) shows this even more with a situation can be called but hilarious (or sad depending on your mood).
- OS is smooth to an excess, a pleasure to use for real
- Updates are frequent but never bear real innovation or massive changes nor solve basic issues (Keyboard input for Traditional Chinese with Pinyin was requested since 2011 and that request reiterated several times without Microsoft ever caring). Every update boasts one or two big changes at max.
- Total lack of changelogs for lots of apps and OS. You never know what's been added or removed. It makes you feel lost in space. MSFT programmers must be lazy at tech writing.
BB
The underdog. I consider it to be one of the best, most secure OS' installed on inadequate devices with RIM having missed the train of full screen devices and phablets (and somewhat still confused about it). The day BB does a good phablet i'll throw myself on it.
- Compatible with Android apps (and with basic security measures to check those apps)
- Stable OS designed for business
- Dedicated servers with real security in place. Not perfect but better than all others.
- Professional UI designed for business and communication (unlike the Hello Kitty feeling o iOS and Android).
- Lack of apps
- Lack of appealing devices (who really wants those small screens with a hardware keyboard today?).
- Lack of customization
It's not an exhaustive list of my thoughts but i have no time and found this thread interesting.
I'd love to own a BB that has a 6" screen with the possibility to add the few Android apps i need to be productive.