The good:
1. QWERTY messaging keyboard
2. 2 megapixel camera, supports video
3. supports 3G data
4. you don’t have to remove the battery to get to the built-in microSD memory card slot
5. very good quality of sound, especially for MP3s
6. instant messaging for AOL, MSN and Yahoo, as well as SMS and MMS messaging
7. the camera on the Samsung Rant is mediocre, but not as bad as some of Samsung’s previous models.
8. 1000 letters per box
9. the speaker is louder and the sound is clear enough
10. can be used as a USB flash, for transport data, especially because it’s not requiring any drivers to connect it to a pc.
11. supports up to 16GB memory (microSD / TransFlash)
12. voice dialing technology / voice recognition
13. Wireless Backup restores contact information if the phone is lost, stolen or damaged (not really sure if it’s working with Koodo)
14. support POP3 / IMAP4 / SMTP
15. phone book Capacity: 600 entries
16. Bluetooth 2.0
17. Nice feature: when you slide the phone open, the screen becomes horizontal automatically
18. can make folders and play lists with music player
19. depending on how you arrange One Click, it can be as little as 2 clicks to text messaging with no scrolling though menus
20. voice memo for short recordings (60 sec)

The Bad:
1. The keyboard’s key are made of rubber
2. You have to remove this cover to access the built-in microSD memory card slot
3. 2.5mm headphone socket instead of the more popular 3.5mm type
4. the display looks something like an older tech passive matrix type instead of 262k color TFT display which Samsung are trying to convince us they are using on this cell model
5. used for playing MP3s the battery is discharging very fast
6. not WiFi compatible
7. screen resolution only 176 x 220 pixels
8. multimedia options are very basic
9. I wish the keyboard were smart enough to enter the corresponding symbol key when I held down a letter key, but instead this action did nothing at all
10. the Web browser on the Samsung Rant is underpowered and fairly slow
11. little bit slow and obvious BIG!
12. the reception for calls is not great…especially if you’re in a basement
13. IT’S NOT GSM – this means it doesn’t have a SIM card (Dual-Band: CDMA 800 MHz, CDMA PCS 1900 MHz)
14. the phone doesn’t come with any game installed (Java platform)
15. you can’t assign MP3s as ring tones also the originally ring tones are not so many (only 20) and not so pretty
16. the Alarm it doesn’t ring if the phone is turned off (you can’t turned it off during the night time)
17. no flash for camera
18. without adequate light you can’t see the outline of the actual keys themselves on the qwerty keyboard
19. can’t change the menu theme
20. the keyguard only automatically activates itself if you’re at the main menu – you run a great risk of dialing friends and strangers on accident
21. only 32 characters for New Events Scheduler / New Tasks

Summary:
The Samsung Rant is an good option for Music Cell Phone & Quick text-messaging Cell Phone Fans.

But should YOU buy this phone? Will you be happy with it? It entirely depends on what you want in a cell phone. Surprisingly, it also depends on what you want in a service plan. For me it’s a good phone. The cons are more of a heads up. None are a deal breaker for me. There is so much I like about his phone, I’m willing to deal with a few quirks. Nothing’s perfect! I’ll be enjoying this phone for at least the next two years without any regrets.

Updates.
Read this article for details how to connect Samsung Rant (M540) to a computer.
Here a working method, if you’re wondering how to receive E-Mails as SMS for FREE on your mobile. (April 2010)

You will get allerted right away for: Speed traps, speed cameras, red light cameras, school zones, DUI checkpoints – POI. The prices are little bit expensive (http://www.phantomalert.com/) but you can seat back and relax while you’re driving :)