Congrats on the a7 IV! Honestly, if you are doing events where you cant afford to miss a shot, I always recommend staying with native glass. I have used both third-party and Sony lenses for years, and while the savings are tempting, the reliability of Sony FE 24-70mm f/2.8 GM II is unmatched. Quick tip: Always prioritize the autofocus communication between the lens and body. Third-party options like the Sigma 24-70mm f/2.8 DG DN Art or the Tamron 28-75mm f/2.8 Di III VXD G2 are excellent for the price, but they can occasionally hunt in low light or miss tracking during fast street sessions. The GM II is actually quite light and is the safest way to ensure you are getting the most out of that a7 IV sensor without any compatibility hiccups down the line. Stick to native glass for mission-critical work, basically.

Jumping in real quick since the price gap here is massive. Before you pull the trigger, how tight is your budget exactly? Also, do you find yourself needing that 24mm wide end often for your travel shots? If you can settle for 28mm, the Tamron 28-75mm f/2.8 Di III VXD G2 is much easier on the wallet and your back. Just wondering if you really need the f/2.8 speed for those indoor gatherings?

Just catching up on this thread. Tbh the Sony GM II is incredible but spending over two grand right after buying a new full-frame body is a lot to swallow. I am always a fan of the used market for getting professional results without the massive debt, but before I give you a full recommendation, I gotta ask... what is your actual hard budget for this? Also, are you mostly shooting in well-lit areas or do you really feel like you need that f/2.8 for the indoor family stuff? I have seen some people get great results with the Sigma 28-70mm f/2.8 DG DN Contemporary which is way cheaper and lighter than the Art version. Or even the older Sony FE 24-105mm f/4 G OSS if you dont mind losing a stop of light for extra reach. Let me know your price ceiling so I dont suggest something that is gonna break the bank.

Been thinking about your dilemma for a few hours now and @Reply #2 - good point! Budget is a huge factor but let me share what I learned the hard way. Years ago I brought a cheaper third-party lens to a high-stakes indoor event and the autofocus just couldnt keep up. I missed some incredible shots of the family laughing because the lens was hunting for focus right at the peak moment! It was honestly heartbreaking. What I learned is that for events and street photography reliability has to be the top priority. My current setup is definitely a bit heavier and it was a big investment but the way it communicates with the camera is basically magic! It makes the shooting process so much smoother and honestly just more enjoyable. Professional results really come down to having equipment you can trust 100% of the time. Once you experience that instant lock-on you wont ever want to go back to anything else... it is a total game changer tbh!