Jumping in here because i've dealt with that eARC nightmare before and it's the absolute worst. Since you have an X90K, sticking with Sony is the only way to guarantee that one-remote bliss without the lag. The HT-G700 you mentioned is okay, but it's getting a bit old and sometimes the mids feel a bit hollow. Ordering this week is smart because you dont want to be troubleshooting while your folks are visiting. Heres what id look at instead:

• Sony HT-S2000 3.1ch Dolby Atmos Soundbar is a newer release that focuses heavily on dialogue clarity. It has dedicated drivers that reduce distortion when you crank the volume for movies.
• If you can find it on sale, the Sony HT-A5000 5.1.2ch Dolby Atmos Soundbar is the top-tier pick for your setup. It has up-firing speakers that actually bounce sound off your ceiling for real height effects.
• You might consider the Sony SA-SW3 Wireless Subwoofer down the line if you feel like you need more punch, but the S2000 is already a massive upgrade over Vizio. Technically, these newer bars use a proprietary Vertical Surround Engine that fills the room way more effectively than those budget bars ever could. It makes a huge difference for that tinny sound you're hearing.

^ This. Also, just saw this thread and gotta say... be really careful about your HDMI cable. I once spent a whole weekend fighting eARC drops only to find it was a bad cord. I would suggest looking at the Sony HT-S2000 3.1ch Dolby Atmos DTS:X Soundbar for your X90K. It handles dialogue way better than those budget brands. Just make sure to use a high-speed cable or you might still get those annoying cutouts.

honestly i've had so many issues with eARC handshakes failing on those mid-tier bars lately. it is super disappointing when they just stop working after six months and i'm always worried about the cheap internal power boards failing unexpectedly. a few things to consider to make sure you get the right setup:

• do you have floor space for a separate subwoofer?
• are you planning on adding discrete rear speakers later on?

Honestly, the Sony HT-G700 3.1ch Dolby Atmos DTS:X Soundbar is a solid mid-range pick, but since you have an X90K, I would suggest looking at the Sony HT-A3000 3.1ch Dolby Atmos Soundbar instead. It usually sits right at your 500-600 limit and the integration is just smoother. I've spent way too many nights troubleshooting eARC drops with mixed brands, and staying within the Sony ecosystem is really the only way to keep your sanity. Here are a few things you might want to consider before buying:

• Make sure to prioritize models with Bravia Sync. Since you have a Sony TV, the soundbar settings will actually show up in your TVs Quick Settings menu. No more extra remotes.
• Be careful with older models like the G700 because they lack the Acoustic Center Sync capability that your X90K actually supports. This feature lets the TV speakers work with the bar for better dialogue.
• I would suggest checking the Sony HT-S2000 3.1ch Dolby Atmos Soundbar if you want to save some cash, though it lacks a dedicated sub, which might make those action movies feel a bit thin.
• Be sure to use a certified HDMI 2.1 cable. A lot of those connection drops are actually just bad cables failing to handle the eARC handshake. Tbh, the dialogue clarity on the A-series bars is a massive step up from Vizio. Sony uses some specific processing to lift the voices so they dont get buried by the background music. Just make sure you update the firmware as soon as you plug it in or the CEC might act wonky at first. It makes the world of difference when the hardware actually talks to each other properly...