I love our Seio 2600, and to this date have not had a problem with them (going on three or four months). Would I have prefered a Tunze? You bet. Would my wallet allow it? No flipping way. I think as far as water movement, Seios are the best value you can find. We clean ours every other month in a vinegar bath and take a toothbrush to it afterwards to ensure no issues, but we do that with our MaxiJets, Mag 9.5 return pump and the Via Aqua 2600 Skimmer pump. In my mind, its sort of like getting oil changes on your car - can you go more than 3000 miles or 3 months without an oil change? Yeah, one of my friends has a car running that hasnt had an oil change in 3 years! But will the car last as long without regular maintenence? Probably not (there are no absolutes when it comes to things like that. Theres always the fluke that slips through the cracks).
So my personal opinoin for your 75, I'd reccomend at least the 1100s as well. You cant really compare gph for gph between the Seios and MaxiJets because with the Seios, the flow is much wider and more dispersed. If you go with the 1100s or even 1500s you can always dial the flow back a bit. But, as brought up earlier, if you're handy and have some time on your hands, the MaxiJet Stream Mod would be a great way to save some money and achieve greater flow coupled with the wider more dispersed flow.