Top companies like LG, Sunpower, Canadian, Trina, Panasonic, Hyundai etc compete very hard to make the most efficient and longest lasting large (300w+) panels for residential and commercial use. I don't think they care much about the smaller panels, so they don't get much of the R&D dollars. IOW, I expect a large panel from a top manufacturer to outproduce and outlast the smaller panels sold under various re-sellers names. In full sun you probably won't see much difference, but I'd bet the newer technology is better at dealing with shade, heat, cold etc...
This is all just a SWAG...