I use it. I like it. Motorcycles to lawn mowers to trucks.
Few examples:
80 Yamaha XS1100 with bad mix match carbs (4) but I had a parts bike. Carbs were attached to the engine but no air cleaner and sitting outside for several years. Pulled them off and sprayed them down with some carb clean I had and bolted them to my bike. Can of SeaFoam in the tank and fired up. Ran rough, but as the tank emptied it was running better. Next fill it was running great.
Another, my 01 Ram 1500 with a 318. Wouldn't idle when cold. Just stall. Dumped a can down the T/B and at 1/2 can or so I flooded it. Let it sit and then fired it up and smoke like a son a *****. Ran good after that. Been a couple years now and no issue.
One more, had an 07 Ram 3500 with a 5.9 Cummins. Bought used. Had it a few months I guess and it bent a pushrod Apparently the engine was carboned up from excessive idling the PO must have done. After the shop fixed it (on warranty) they bent another on a test run. Fixed it. Told me they could clean the engine but it was expensive. I dumped a can of SeaFoam in the tank and drove it. 2nd tank, new can. 3rd tank, new can. Around half way through that tank I was rollin around 70 MPH when my engine coughed, barked, shook a second and ran smoother than it did since the day I bought it. Whatever it was it **** it out.
So... I believe in SeaFoam. My bikes and vehicles get a can run through every spring.