ACE 300i or 400i: which Garrett is the smarter buy?

Display

Winner: Garrett ACE 400i

Both machines use Garrett’s familiar ACE LCD interface, so neither feels “premium” in the modern touchscreen sense, but the 400i gives you a more informative, more useful display in the field. The 400i’s higher-resolution target ID scale is better for separating good conductors from junk, especially when you’re working trashy pasture or a hammered UK park. On the 300i, the screen is clear enough and perfectly usable for beginners, but the 400i’s extra granularity makes target interpretation easier when the ground is busy. If you’re trying to decide between a good dig and a pass, that extra ID detail is worth having.

Performance

Winner: Garrett ACE 400i

This is the big one. The ACE 300i runs at 8 kHz, which is a solid all-round frequency for coins, relics and general detecting. The ACE 400i steps up to 10 kHz, giving it a little more sensitivity to smaller and lower-conductive targets such as hammered silver, thin buttons and some jewellery. In practice, the 400i is the more capable detector in demanding UK conditions, especially when paired with its DD coil and better iron handling.

The 300i still performs well for beginners and casual users, and its 8 kHz operation is perfectly respectable for coin shooting. But the 400i wins because it offers more flexible discrimination, better target separation and a stronger chance of hearing faint targets in mixed ground. If you detect ploughed fields, old pasture with iron contamination, or you want to squeeze more from difficult sites, the 400i is the better tool.

Build quality and design

Winner: Tie

Both detectors share the same ACE family design language: simple, lightweight, easy to assemble and easy to learn. They’re both built around a compact control box, S-rod shaft and comfortable arm cuff, with a balanced feel that suits long sessions. Neither is fully waterproof, so the control box must stay dry, and both are better described as weather-resistant rather than submersible.

In terms of physical feel, there is very little to separate them. The 300i and 400i are both around the same weight class, which makes them friendly for newcomers and younger users, and both are easy to swing for several hours. The 400i’s included coil and extras make it feel slightly more “serious”, but the underlying build quality is essentially the same. For durability and ergonomics, this is a draw.

Battery life

Winner: Tie

Both detectors use AA batteries, which is a genuine practical advantage for UK users because replacements are cheap and easy to source anywhere. Runtime is broadly similar, and in real-world use you can expect a full day’s detecting from a decent set of alkalines or rechargeables, depending on backlight use and signal volume. There isn’t a meaningful battery-life edge here.

If anything, the simplicity is the point: no proprietary pack, no awkward charging dock, no waiting around. For field use, both are equally convenient. This is another dead heat.

Price and value for money

Winner: Garrett ACE 300i

At £276.00, the 300i is £103.94 cheaper than the 400i, and that gap matters. For a first proper detector, the 300i gives you the Garrett ACE experience at a much more approachable price, with enough performance to find plenty of coins, relics and lost jewellery. If you are upgrading from a toy detector or buying your first serious machine, the 300i delivers stronger value on a pure pounds-to-performance basis.

The 400i is still good value if you’ll use its extra capability, but it’s harder to justify if you mostly detect easy sites or only go out occasionally. In that case, you’re paying for features you may not fully exploit. Value goes to the 300i because it gets you most of the way there for noticeably less money.

Features and target ID accuracy

Winner: Garrett ACE 400i

This is where the 400i earns its extra cost. It has better discrimination options, more precise target ID, and a stronger ability to pick out good signals around iron. That matters a lot in the UK, where old sites can be full of nails, coke, foil and modern trash. The 400i’s DD coil also helps with target separation and ground coverage, which is a real advantage on rough pasture and ploughed land.

The 300i’s concentric-style setup is fine for clean ground and easier sites, and it is generally simpler for beginners to interpret. But if you care about target ID accuracy, especially on marginal signals, the 400i is the better machine. It is simply more informative and more capable when the ground gets messy.

Overall user experience

Winner: Garrett ACE 400i

The 300i is the easier recommendation for absolute beginners because it is cheaper, straightforward and still very effective. But the 400i is the better detector to live with once you understand what you’re hearing. Its extra sensitivity, better discrimination and improved target separation make it more rewarding on real UK sites, where good finds are often masked by rubbish. If you want a detector that you can grow into rather than grow out of, the 400i is the stronger long-term choice.

Overall summary: buy the ACE 300i if you want the best entry price and a dependable all-round detector. Buy the ACE 400i if you want the better-performing machine, especially for iron-infested or challenging ground. For most detectorists who can stretch the budget, the 400i is the definitive winner; for value-focused buyers, the 300i remains the smarter spend.