I’d wholly recommend the SX-335. I have the identical one from two years ago. My wife initially got me the one without all the stainless internals and side burner and we swapped it out. I grill at least 3-4 times a week so it was an investment for me. It replaced an older 4 burner Weber summit. What I noticed was that the cooking area was within around 60 sq in of my older summit. I’ve never ran out of space on the grill yet when entertaining (and we throw some big parties) and it doesn’t suck down propane nearly as fast as the 4 burner. The 4th sear burner is great for getting it up to temp quick. All the stainless cleans up very easy and the grill light is very convenient at night. So is having the side burner, especially if you are gonna cook something that would stink up your house normally, just do it outside. I’ve had it for two (actually might be three) years and obviously not one problem with it. I did not get a weber cover as they are junk, got a brand called “King Kong” off Amazon because the quality is much higher and they don’t crack and fall apart after a year like the weber ones do.
Long winded, but can’t go wrong with the 335. With the 4 burner you’re gonna go through propane (or gas) way more.