The Quick Verdict
Honestly? These two together is the setup — the S70 on your wrist for course strategy and the Z30 in your pocket for the exact pin number. Combined you're at $1,200, which isn't nothing, but this is what a lot of serious players actually run. Buying just one? The S70 is the better single device — it gives you useful information on every shot, not just when you're already in range and know where the pin is. The Z30 is exceptional at its one job, but the S70 covers more of the round.
What They Actually Do
The S70 is a full-color GPS watch with hole maps, hazard layouts, and an AI virtual caddie — it lives on your wrist and shows you the whole picture before you hit. The Z30 is a laser rangefinder — you point it at the flag, pull the trigger, and it tells you exactly how far away it is. Both are Garmin products, both are tournament-legal with slope disabled, and both live in the Garmin ecosystem. The Z30 even has Range Relay, meaning it can send its laser reading directly to a compatible Garmin device on your wrist.
The Real Tradeoffs
Precision vs. Useful Information
The Z30 is accurate to ±1 meter to a specific target you choose. The S70 gives you front/center/back yardages to a fixed GPS point. For a tucked pin 164 yards away on a firm green where three yards matters, the rangefinder wins. For everything else — figuring out whether to lay up short of a bunker, carrying a water hazard off the tee, choosing between a 3-wood and a 5-iron on a long par 5 — the GPS watch gives you more of what you need.
Speed of Use
You can't overstate how much faster a wrist GPS is during a round. Glance down, you have your yardage. With the Z30, you're reaching into your bag or cart holster, raising it to your eye, finding the flag through the scope, acquiring the target, reading the number, then putting it away. None of that is difficult, but on a busy Saturday with groups stacked behind you, the watch wins every time. The Z30 shines on approach shots when you have a moment to breathe.
What You See Before You Swing
This is where the S70 does something the Z30 categorically cannot do. You're on a tee box you've never played before — 420-yard par 4, dogleg right, water running along the entire right side. The S70 shows you the full hole map: where the water starts, how far the fairway bunkers are, what the carry is to clear the corner. You can plan your shot before you even pull a club. The Z30 is useless here — there's nothing to point at, and it won't show you the hole layout under any circumstances.
On the other side: you're 158 yards out, the pin is front-right on a tiered green, and you want to know exactly how far the flag is versus the center. That's the Z30's moment. The S70 gives you center green. The Z30 gives you the flag.
The Garmin Ecosystem
This is a same-brand pairing and it matters. Both sync to the Garmin Golf app. The Z30 has Range Relay — it can transmit its laser measurement to a paired Garmin device. So in practice, you range the pin with the Z30, and the exact number appears on your wrist without you digging out a phone or doing mental math. That integration is real and it's a genuine argument for running both in the same bag.
The S70 also has a virtual caddie that factors in wind, elevation (via built-in barometer), and your swing history to recommend a specific club. The more rounds you log, the smarter it gets.
Cost of Ownership
The S70 is $699.99. Green contours and enhanced maps require a Garmin Golf membership at $99.99/year — that adds up to roughly $400 over three years on top of the hardware. The Z30 is $499.99 with no subscription and no ongoing cost. Its CR2 batteries last up to a year on a single cell. Together you're looking at $1,200 upfront plus the optional membership, which is real money — but each device covers a gap the other leaves.
Tournament Legality
Both are tournament-legal with slope disabled. The S70 has a dedicated tournament mode. The Z30 has verified slope disable to pass the rules check. No issues with either.
Who Should Get Which
Get the S70 if you play a variety of courses and want a device that tells you things you don't already know — hazard locations, hole layouts, shot tracking, scoring. If you're the kind of player who gets to a new course and wants to understand the hole before teeing off, the watch pays for itself in smarter decisions. It also tracks your fitness, stores music, and handles contactless payments, so it pulls double duty off the course.
Get the Z30 if you play the same handful of courses regularly and already know the layouts cold. You know the hole. You just need to know exactly where the pin is today. The Z30 answers that question better than anything GPS can. It's also the right call if you want a simple, single-purpose device that you never have to charge — drop in a CR2 battery and you're good for a year.
Get both if you're serious about course management and shooting your best scores matters enough to invest in the full setup. The S70 handles strategy from tee to green. The Z30 handles precision on approach. With Range Relay connecting them, they work as a system — not just as two devices riding in the same bag.
The Bottom Line
The S70 and Z30 are genuinely complementary, and the Garmin ecosystem makes them work better together than any other GPS-plus-rangefinder pairing on the market. If you're buying one, take the S70 — it's useful on more shots, more holes, and more courses than the Z30 can match as a standalone device. The Z30 is outstanding at one specific job, but the S70 covers enough of that job to survive without it.