The Quick Verdict
Get the Bushnell A1-Slope. Yes, it costs $100 more — but you're getting USB-C recharging, a water resistance rating you can actually verify (IPX6), and a form factor small enough that you'll stop leaving it in the cart. The Callaway CSi Pro is a solid rangefinder at a better price, but its battery situation is a question mark and "water-resistant" without a spec is a soft promise. The A1-Slope earns that extra hundred. Check price at TGW →
What They Have in Common
Both shoot to ±1 yard accuracy, run 6x magnification, have an LCD display, and include slope with a legal-play switch. At this tier, that's the expected package — slope on/off, pin-finding optics, and enough range that you'll never run out of yardage before the flag does. Neither is going to embarrass you on the course.
Where They Differ
Size and Form Factor
The A1-Slope is Bushnell's smallest rangefinder ever — 3.75 × 1.42 × 2.36 inches and 5.1 oz. That's genuinely pocketable, not just "fits in a bag pocket if you shove it." The CSi Pro is noticeably chunkier at 4 × 2.75 × 1.5 inches and 5.6 oz. Neither is heavy, but the Bushnell disappears into a front pocket in a way the Callaway doesn't. If you're constantly reaching into your cart bag to dig out a rangefinder, size matters more than you'd think mid-round.
Battery and Charging
This is probably the biggest practical difference. The A1-Slope is USB-C rechargeable and rated for 50+ rounds — roughly 3,000 actuations. You charge it like your phone and forget about it for months. The CSi Pro doesn't publish its battery life at all. That's not necessarily a dealbreaker — lots of rangefinders run a standard CR2 battery for a full season — but you genuinely don't know what you're getting. CR2s are easy to find and cheap to replace, but having to remember a spare is its own friction. Callaway not publishing the figure is a little odd for a tier-3 product, and I'd guess it's because USB-C recharging is the marketing story right now and a CR2 unit feels dated by comparison — but I don't work at Callaway.
Water Resistance
The A1-Slope is rated IPX6, which means it can take a jet of water and survive. That's a real spec with a real standard behind it. The CSi Pro says "water-resistant" with no rating attached. On a drizzly morning round that's probably fine, but "water-resistant" without a number is doing a lot of vague work. If you play in genuinely wet conditions, IPX6 is the better answer.
The CSi Pro's Club Selection Feature
The CSi Pro has something called CSi — it gives you a club recommendation based on your shot distance. It's a feature; whether it's a useful one depends on the golfer. If you're already dialed in on your yardages and just need the number, it's noise. If you're earlier in the process of learning your distances, it might actually help frame the decision. Worth noting, not overselling.
Who Should Buy Which
Get the Bushnell A1-Slope if:
- You want a rangefinder you can drop in a shorts pocket and forget is there — it's genuinely small enough for that
- You tee off in October when it's raining sideways and want an actual IPX6 rating, not a marketing promise
- You hate dealing with batteries — USB-C recharging is a real quality-of-life upgrade over a drawer full of CR2s
- You play 3-4 rounds a week and want something with enough charge capacity that it becomes one less thing to think about
Get the Callaway CSi Pro if:
- You want a capable, accurate rangefinder with slope and you'd genuinely rather keep $100 in your pocket — it shoots straight and gets the job done
- You're newer to tracking yardages and might find the CSi club selection feature useful while you're building your distance map
- You're buying a rangefinder for a casual golfer you know — it's good enough that they won't outgrow it, and the price is easier to justify as a gift
The Bottom Line
These are both honest tier-3 rangefinders with slope, 6x glass, and ±1 yard accuracy. The CSi Pro isn't bad — it's just that the Bushnell A1-Slope answers more of the practical questions: what's the battery life (50 rounds), what's the water rating (IPX6), and how small is it (very). The $100 gap is real, but so is the difference in what you actually know about what you're buying.