Pros: This is an all-in-one solution for Nintendo DS Lite owner. Not only can you play Nintendo DS games with this, you can also play Gameboy Advance games with this.
The product is neatly packaged as well. Very professional packaging!

Cons: It lacks support for microSDHC (microSecure Digital High Capacity) cards which means it can only support microSD cards of up to 2GB capacity.

Other Thoughts:

Bottomline: This is a great combo product for any Nintendo DS Lite owner. If you want an all-in-one solution for you Nintendo DS Lite, go ahead and buy this!!!

Pros: This combo pack has everything a DS owner could ever need!
You get both DS and GBA games, along with all the homebrew made for the DS (movies, emulators, Linux).
Also, the extendable stylus that comes with is way better than the one of my DS.
I have the "phat" DS, so I can confirm this "lite" 3-in-1 pak works just great in my DS too. You only need to remove one philips screw and the front cover.

Cons: - lack of SDHC (SD cards over 2gb) support is a tiny one, but as 2gb is plenty of space for me, not a big deal

Other Thoughts:

Bottomline: Even though some of these NYE carts have had trouble, this newest batch has none.
I have had absolutely no trouble, everything works and saves fine.
So, to sum it all up, if you want both DS, GBA, and movies & music at the same time with typical DX budget price, yes!
PS: Use the 1.72 kernel with this new edition.

Pros: combined slot 1 and slot 2 solution.
good price.
supports game roms, homebrew, gba roms.
has soft-reset and cheat mode.
3-in-1 support included. Cam be used as extra ram for opera, dslinux and SNES emulator.

GREAT rom compatibility good basic features.
3-in-1 can be used as a standalone card, once GBA rom loaded into it.

software based on moonshell can play mp3 and videos in dpg format.

comes with a good stilus and some other junk (finger stilus and screen cleaner)

Cons: many people seem to have problems with the new revision (NYE) ... I am lucky, because here it works great.

No SDHC support (so maximum of 2 GB Micro SD card supported)

Bad support from the ez team.
Software is not that intuitive. Many modern features are missing (in game menu etc.)
softreset not allways works.
cheat mode works, but its usability should be improved.

Other Thoughts: go to the homepage of the ezflash team, and download the latest kernel (1.70 as of now ... 1.72 beta has no cheatmode)
first only copy the update.bin file, boot while holding the r button and update flash by again pressing r. then copy the rest.
support can be foung at http://ezflash.sosuke.com/ there is also these 2 articles:
http://ezflash.sosuke.com/wiki/index.php?title=ALL_YOU_NEED_FOR_EZV
http://ezflash.sosuke.com/wiki/index.php?title=EZFlash_V_quickstart_guide

get also rudolphs exploader ... it supports the new 3-in-1 and it auto patches GBA roms, and can load ROMs <=16 MB to the ram (which is MUCH faster)

Bottomline: I bought it mainly because I thought that it is tightly integrated with the 3-in-1 ...
well the integration is not that tight, and the featureset is also not that great.
But for me it works well, and all basic funcrions work. (I am not suffering from NYE problems as save malfunction, and sleep mode anomalies as others.)

Pros: It will open up new worlds of uses for your Nintendo DS-Lite, saved games, music, e-books, and movies. The rumble pack also provides expansion RAM for use with things like the DS Browser.

The software allows rapid control of the rumble strength and launching of all kinds of files.

Packaging is professional with some nice extras like a telescoping stylus that fits into the original slot and is easier to remove than the original stylus.

Cons: The build quality is good, but the slot 1 card is a tight fit in the DS-Lite, especially with the Micro-SD card installed.

The instructions are rather light. You will want to read on some Nintendo DS forums and the ezflash.cn site before you install it the first time. Expect that the manufacturer's notices may not make obvious sense if it's the first time you're using it.

Other Thoughts: It's a little annoying to have to pull the micro-SD cart from the tight fit in the Slot 1 cartridge to write things onto it with a computer. Take care doing this as the micro-SD cards are fragile.

It is essentially drag-and-drop though. If you drop files onto a Micro-SD card, and then put it in the EZflash card and put that into the DS, you'll be playing right away.

Bottomline: A nice combo for someone wishing to expand his NDS Lite with everything needed to use homebrew/saves/movies/e-books. Nice accessories included as well.