I have and use both. I have a Craftsman Zip Code saw and use a sled for accurate cuts. Though because of my tiny shop, I mostly use a guide and circular saw (Milwaukee with a good Freud blade) to break down sheets of plywood, and sometimes to do most all the cuts needed for a project. With the guides I can split a pencil mark if I need to. And if I measure accurately enough, I can stack multiple pieces and feel practically no difference in size. I also have made a panel gauge (like a LONG marking gauge) that I can set to make repeat cuts, as it will set the edge of the guide the same distance from the edge of the plywood. I keep dropping hints for a tracksaw around Christmas and birthday time, but nothing yet...
And I just posted this info on the guides and links to another previous post for my cutting table in this thread:
I can set up the table behind my truck, slide plywood out onto the cutting table, cut it down to size, then carry it around to my shop.
As for my guides, I built my guides from a full sheet of 3/16" hardboard and three 6" wide strips of good
1/2" plywood. Key thing building these is to make sure the 1/2" plywood strips are STRAIGHT. You can use the edge of the sheet of hardboard as a guide to rip the strips from the 1/2" sheet, or one of the commercial guide bars available. Then, on a FLAT surface, I glued the 3 strips onto the hardboard leaving enough room to run the saw down both sides of all 3, giving me three 8' long two-sided saw guides. I cut one into a 3' & 5' guide, and put the third one away for a backup/extra. Even added a cleat under the 3 footer, making sure it was square and I can just butt it up to the edge of the plywood and get a square cut quickly.
And if I change blades and the guide no longer matches or if the edge got dinged, I run the edge of the guide on my tablesaw rip fence, set so that it rips a blade thickness from the 1/2" ply only, then recut the guide edge with the circular saw.