I have both. The E4 downstairs and a SEPE upstairs. Beleive it or not I like my SEPE more than the E4, don't ask me why because I don't know the reason myself. The SEPE gets used for everyday cleaning and the E4 once a week. As far as quality, I think they are both quality machines with the exception of the plastic clips on the E4 hose. To me the SEPE is not as heavy as the E4. I just replaced a latch on my aunts rainbow in august and it was bought new in 1986 and it was used EVERYDAY and I would hate to say how many times the latch had been latched and unlatched. For it to last this long that has to say something about the quality of a rainbow. If you can swing the money I would go ahead and get the new E4.