never really noted the look or smell, both work wonders however. As said above, one designed for foam pads other for microfibers. I would suspect one is a lighter version for laundry use.
Use em both. Love em both.
Got a new sytem with XMT Pad Cleaner. After the dirty pad is sprayed add a small amount of water to the pad and knead it in deep. You'll get some light suds. Let sit and then rinse. My stained pads look almost new doing this.