Are we talking Spinner or SSD?-MilesAhead
forgot to state that - it's a spinner 
-tomos
If you have a stable setup it may be advisable to partition. My experience is with MBR type drives. All I have done with GPT so far is carve out a data partition using the Disk Manager in Windows. How much it complicates things if you have a lot of partitions on a GPT drive I do not know.
But I say stable setup because then you have an idea how large to make the system partition. The tendency is to make it pretty lean. But if you like to install lots of utilities then over time you may find the size that seemed adequate starts to feel a bit tight.
That aside, on an MBR setup partitioning has the advantage you can just make an image of your system partition and back up your data without including it in the image. I asked about the SSD/Spinner because if you add and delete a lot of programs trying things out then you may find you want to defrag the partition periodically. If the free space in the partition is too small the defrags can take longer that ordinarily required due to the extra shuffling around in the tight space. If it is SSD you may not defrag at all. Although I hear now there are specialized SSD defrag tools. But I suspect it is much more noticeable if a spinner is fragmented than an SSD.
If you search the DC forums I believe awhile back Shades posted a very detailed description of the scheme he uses for partitioning. I recall it being very well thought out and I am sure he has used it for some time. So it is tried and tested.
One advantage of just leaving everything one big C: partition is if you install and remove stuff frequently and do lots of stuff like create VMs that you delete after awhile, then having a lot of free space on the partition makes for fast defrags. I try to keep my free space close to 70% so that I can do a quickie Auslogics defrag in about 5 minutes. I don't have all that much in the way of "data" per se. It is more like junk that piles up. Plus all I have is a Laptop now. I have to carry everything around with me. So I figure my backup image has the data as well as the system.
In which case you should probably be taking your advice from somebody else anyway.
