I bought the es4s on the 21st of this month. I liked them so much that I immediately decided to upgrade to Zs10s. My test was theoretical, I was wondering how to decide if they sound better than my es4s. I connected one of es4 on one side and Zs10 on the other side. I thought it sounded exactly the same. I was wrong . The Zs10s overpowered and filled in the gaps in bass and mids on listening. It was only when I plugged in one at a time that I could actually hear the difference. Wow! If you can't afford the Zs10, the es4 is more than perfect. If you can get extra money for it, I say go for it
Upgrade Your Music Experience with XiaoMi True Wireless Earphones 2 Basic - Longer Battery Life and Superior Sound Quality (White, International Edition)
341 Review
Headphones Sennheiser CX 300-II, black
318 Review
Upgrade Your Audio Experience with Samsung Galaxy Buds+ Plus: True Wireless Earbuds with Improved Battery and Call Quality in White, including Wireless Charging Case and Velvet Pouch.
320 Review
Huawei Freebuds Pro MermaidTWS with Active Noise Cancellation - Silver Frost
299 Review
Sennheiser CX 80S In-Ear Headphones with One-Button Smart Remote - Black: A Powerful Sound Experience
20 Review
Sony MDREX155AP In-Ear Earbuds Headphones/Headset with Phone Call Mic, White (MDR-EX155AP/W)
36 Review
Sony WI-C310/B Wireless In-Ear Headset with Built-in Mic for Phone Calls - Black
31 Review
Sony MDR-ZX310AP ZX Series Blue Wired On Ear Headphones with Mic: Immersive Sound Experience
48 Review