Side by side

Formex Reef GMTvsGrand Seiko SLGA015

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

Reef GMT
FormexReef GMT
MSRP $2,235
SLGA015
Grand SeikoSLGA015
MSRP $12,600
What people say

Owners + reviewers, side by side

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Formex Reef GMT

The Formex Reef GMT is widely praised for its unique porthole case shape, COSC-certified Sellita SW330-2 movement with good finishing, and comfortable quick-release bracelet with on-the-fly micro-adjustment. Reviewers note its robust construction, impressive specifications, and strong value proposition, with a slim 11.4mm profile accommodating 300m water resistance and an exhibition caseback. However, owners widely report the 53mm lug-to-lug span with male endlinks makes it too large for smaller wrists. Some find the bezel action stiff and potentially slippery, and a reviewer desired sharper finishing and edges, deeming the aesthetic too modernist. The GMT variant sacrifices a timing bezel unless swapped, and one owner notes sharp edges on the crown and crown guard. Overall, owners and reviewers highly rate the Formex Reef GMT for its exceptional value and well-executed features, particularly its bracelet system and COSC-certified movement.

From video reviewers

The watch features a COSC-certified SW330-2 GMT movement, which is visible through a sapphire crystal display case back and beautifully decorated. The watch's water-resistance of up to 300m/1000ft is a notable feature. The 42mm diameter may be too large for smaller wrists.

Grand Seiko SLGA015

The Grand Seiko SLGA015 is widely praised for its exceptional accuracy, with owners reporting performance far exceeding the stated 10 seconds per month. The Spring Drive movement's smooth sweep and 5-day power reserve are also noted strengths, as is the lighter titanium case construction. However, some owners find the bracelet extension non-intuitive, and one noted the clasp scratched easily. The watch features a nature-inspired, wave-like dial texture. Overall, owners rate the Grand Seiko SLGA015 highly for its impressive accuracy and quality construction.

At a glance

13 of 29 specs differ
Diameter
Reef GMT42mm
SLGA01543.8mm
Power Reserve
Reef GMT56h
SLGA015120h
Water Resistance
Reef GMT300m
SLGA015200m
MSRP
Reef GMT$2,235
SLGA015$12,600

Full specifications

Case

7 specs
Category
GMT
Diver
Diameter
42mm
43.8mm
Thickness
11.4mm
13.8mm
Lug-to-Lug
47mm
51.5mm
Lug Width
22mm
23mm
Material
Stainless Steel
Titanium
Water Resistance
300m
200m

Crystal & Dial

2 specs
AR Coating
Inner
Yes
Lume
Super-LumiNova
None

Movement

3 specs
Caliber
Sellita SW330-2
9RA5
Type
Automatic
Spring Drive
Power Reserve
56h
120h

Pricing

1 specs
MSRP
$2,235
$12,600
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