different oppinion here which is all you find here most of the time. the marquis will filter ALL the water in that 630 from floor to surface more than 60 times a day. that is moving alot of water!! that is during two filtering cycles per day. on the watkins product, hot spring or t.river, the silent flo 5000 pump will completely filter the water only 10 to 15 times per day. i prefer the 60 times during the 2 filter periods. the bottom line is they are both good brands, HOW DO THEY FEEL?? does the 630 have the hk40 jets?? those babys move some water!!! does it have the low e wrap? 6200 is a good price for a 630. my 530 cost me an average of 80 to 90 cents per day in the month of march. the avg temp here in the U.P. was 28 degrees for the month of march.