I use both Arkel GT-54s and some homemade panniers with the Arkel mounts and a few Ortlieb panniers and both are excellent. I have had the Arkels for 13 years and they look new and I commute with some Ortliebs and they are all really good.

Sure an Ortlieb might seem simple but there is absolutely nothing wrong with that in least, it might be simple but in the end it is super durable and reliable You might be paying $190 initially but you will have those panniers for 10+ years so that is less than $19 per year or if you have them for 20 years under $10 a year that is cheeeeeeeeeeeaap. Heck you can spend 10 for a single coffee in a morning, this is 10-20 per YEAR. Not a bad deal at all. Your gear stays dry and the panniers can handle just about anything.

My Arkels are certainly more complex (though they make their own dry bag type panniers that are simpler) but also extremely reliable and long lasting as well. Honestly I couldn't tell you which is better or worse as they are just really well made bags that can stand the test of time.