Pros and Cons: (that I can remember but not an all inclusive list)
Can expand a full a volume to unused non adjacent (same disk) space or space on separate physical disk.
Muti-disk span , mirror or stripped sets capable.
Can break through the 26 drive letter limit and handle unlimited number of disk volumes. However Basic disk using GPT can break the 26 drive letter limit and use manage 128 disk volume. (How many do you need)
Can manage and make changes to volumes without rebooting system.
Not easy to revert back to Basic. (have to back up all data)
Can not run Windows or Linux from Dynamic disks.
Can not read disk data from Windows Home. (issue if your dynamic is shared to a network with XP home clients on them)
May be issues with moving to another machine.
No 3rd party disk management tool support (proprietary Windows)
My opinion - Its only good for say.... 3 reasons
1. Have a 1TB drive (say drive M:) with movies on it and you run out of space. You can convert drive M: from Basic to Dynamic and and add another 1TB disk and span or include it in the same volume M: making it 2TB. That is if you really need or want all of your movies in one volume or directory.
2. You need more than 128 disk volume that GPT manages. (Who really does?)
Lastly 3. Want to do spanning such as software RAID, stripping or mirrored sets through Windows. If you have a basic system doing basic computing you may get away with this as multi-core cpu's may handle the overhead of running the software RAID but....
A. Performance gains of stripped sets are minimal as Gamers, Video and graphics pro's and CAD users don't generally use software RAID and usually will implement RAID cards and/or SSD's to eliminate as much cpu overhead as possible.
B. Mirror sets while providing fault tolerance, eliminates the ability to manage these volumes via 3rd party disk management tools or backing up said disks with any 3rd party backup which could be set for automatic, which in my opinion would be a more customizable and manageable giving the home user more control.
Note: One last possible pro as I understand it, you can create a RAID 0, 1, 5, 10 using Dynamic disks and divide one physical disk into several volumes and being able to pick and choose which volumes to use as long as they are equal in size. ie: an equal size volume from 1-5 separated disks that do no take up the whole disk space on each. I don't think there is any possible way to implement software RAID in Windows using Basic disks without converting to Dynamic but I believe you can do so using some form of hardware RAID controller but you have to even then use the entirety of each Basic disk in the array without partitioning.
To me it does not seam like that great of a choice on a small home system or home NAS. I am not sure what benefits there are for the enterprise market in the real world. Maybe there are some if you are running a Windows based server with 100's or 1,000's of physical disks.