So I finally picked up a used S5ii a couple months ago and honestly I love the camera but the kit lens is starting to feel pretty limiting now that Im getting more into street photography and some light travel gigs. Im planning a trip to Japan in November and I really need something versatile that wont break the bank because my gear budget is basically tapped out at around 800-900 bucks max.

Ive been scouring forums for weeks and man the opinions are all over the place. I keep seeing people swear by the Sigma 28-70mm f2.8 Contemporary because it is super light and fits the travel vibe perfectly, but then I read a thread on another site saying the autofocus can be a bit jittery compared to the native Panasonic glass. Then there is the Lumix 20-60mm which is dirt cheap but honestly I feel like I need that constant 2.8 aperture for the stuff I like to shoot at night. It is super confusing because one person says the Sigma is sharp as a tack and the next person acts like its a paperweight.

Here is what I really need:

• Budget: Under 900 USD, preferably closer to 700 if possible.
• Use case: Travel, street, and maybe some environmental portraits.
• Weight: Needs to be relatively compact since I dont want to lug around a massive brick while walking 10 miles a day in Tokyo.
• Aperture: Constant 2.8 would be ideal but Im open to suggestions if something else really shines.

Do I just bite the bullet and hunt for a deal on the Sigma or is there some hidden gem from Tamron or even a used Panasonic lens I should be looking at instead? I just dont want to regret the purchase a week into my trip when I realize the lens doesnt hold up to what I need. What are you guys actually using for travel that feels like a decent value?