First welcome to Reef Central!
Second, I can’t help with the MP40 Question, but I run a Jebao SW8 with no issues. I also have a Neptune Wav and a couple Koralia Nanos and haven’t had any issues with either.
The biggest issue people seem to have is longevity. While the pricier pumps are “in theory” designed to last longer, I think about 10 years or so, you may get a shorter lifespan with the cheaper pumps (that’s when it looks at what your personal cost/replacement frequency is). For example, a Jebao SW8 is $72.50 on Amazon right now. An MP40 brand new on BRS is $430. So I can buy about 6 SW8 pumps for the cost of 1 MP40. Say I get two years out of each SW8, that’s 12 years of use instead of the approximate 10 that the MP40 may get.
This isn’t taking into account though, the MP40 you can get replacement wet sides and dry sides soo that’s a plus (but I don’t know the expense)