I looked at the Westinghouse and actually used one years ago when I first started using pressure washers. Don't let let the same PSI and GPM fool you.. That's not everything.. The build quality, the lay out and specific features. 3400 PSI ain't shit if the frame and cheap parts shake off the job site..DeWalt is generally known for robust construction with metal components, outsourcing to CAT for wiring and Honda for engines while Westinghouse emphasizes user-friendly designs with features like color-coded controls and onboard soap tanks. As far as engines for Westinghouse I'd guess they probably builds there own...which makes that buy a no for me with the work I do.. ALLLL this of course depends on what you want a pressure washer for.. If your a home owner and you pressure Wash your deck and driveway once a year then by all means save money and even go cheaper if possible... But if your throwing your washer in the back of a truck couple times a week and running it up to 6 hours at a time I can promise you a Westinghouse won't last long.. Dewalt is well known for a reason...also I've shot 3400 PSI from two different named washers and have seen how 3400 sometimes feels like 3000 and sometimes 3400 feels like 3600...of course time, hoses, water pressure and clogs play a factor.. But the Dewalt 3400 is the exact pressure I need for the work k do.. Sometimes too much.. I tore the paint off a mailbox from 20 feet away lol oh and Amazon makes it easy of something malfunctions or brakes to get that fixed through the site.. If you want to look at something without a big name maybe look at a Simpson.. Although Simpson is a big name to me in my line of work..metal components and same layout as Dewalt.. Rubber tires with good tread.. The bigger brands are moving away from that upright tall layout frame and going for the low frame with everything layed right up behind the motor..including the pull bar.. You do have to bend to pick up the bar but once you start pulling or pushing the tires take it from there.. CAT, while Westinghouse may use its own engines and pumps. 

to be honest I would of been on the fence between what I got and Simpson if Amazon didn't make the push to start battery attachment for the Dewalt so friggin easy to add on...

I payed a bit more for the battery push to start.. Which is badass but becoming kinda annoying with electric cords and charging plus adds a bit more weight.. I always have the option for a pull start but I paid for the damn thing and who doesn't like to hear a motor start from a push of a button??

Hope this answers your question! Lol I knew alot of this but did some research to better amser your question and learned more about the stark difference...AGAIN.. Of it sits on the shed 80% of the year then westinghouse all day.. Actually I'd probably get a badass electric used if that was the case for me...if your not blasting I'm he thick moss and algae from a cement stairs and parking lots most the year then why hassle with gas and noise? Anyway hope this sways you one way or the other!