Arrma Big Rock 3S BLX vs Losi LMT Son-uva DiggerWhich Should You Buy?

The Arrma Big Rock 3S BLX and Losi LMT Son-uva Digger represent two philosophies of monster truck fun that barely overlap. The Big Rock is built for speed and all-terrain bashing with modern independent suspension. The LMT Son-uva Digger is built for monster jam-style stunts with solid axles that enable wheelies and backflips. Despite sharing the monster truck label, they deliver completely different experiences at the sticks.

The Big Rock tops out at 50 mph while the LMT manages 40 mph. Speed was never the LMT's purpose, though. Its solid axle design sacrifices straight-line speed and handling precision for the ability to perform tricks that independent-suspension trucks like the Big Rock physically cannot replicate. The LMT will wheelie on command, consistently nail backflips off properly built ramps, and pull off aerial maneuvers that make bystanders stop and watch. The Big Rock can catch air and land cleanly, but it's not designed for controlled aerial acrobatics.

Scale and size heavily favor the LMT. As a 1/8 scale truck, the Son-uva Digger measures 22.84 inches long and 17.52 inches wide with massive tires that give it 3.54 inches of ground clearance. It towers over the Big Rock's 20.47-inch length, 14.57-inch width, and 2.05-inch clearance. The LMT weighs 11.13 lbs, over 4 lbs heavier than the Big Rock's 6.77 lbs. This heft helps the LMT land hard from big jumps without bouncing erratically. The weight carries through rotations with momentum, making aerial tricks more predictable and consistent.

A critical difference that affects every outing: the LMT Son-uva Digger is not waterproof. The Big Rock is. If you plan to drive in any wet conditions, morning dew on grass, puddles, light rain, the Big Rock doesn't require modification while the LMT needs aftermarket waterproofing to survive. For a truck at this price competing against a competitive price waterproof option, this omission is hard to overlook. You'll spend significantly more on conformal coating or waterproof electronics to get the LMT to the same baseline.

Both trucks run 3S brushless power, so battery voltage and costs are similar. The LMT accommodates 5000mAh 3S packs for longer runtime, while the Big Rock specs 3200mAh 3S. The LMT's heavier weight means it draws more current, partially offsetting its larger battery advantage. In practice, both trucks deliver roughly similar session lengths depending on driving intensity.

Price clearly favors the Big Rock compared to the LMT. That price gap is significant, especially since the Big Rock is faster and waterproof out of the box. The LMT's premium pays for the solid axle platform, the larger 1/8 scale, the licensed Son-uva Digger body with its detailed graphics, and the unique stunt capabilities that no conventional basher offers at any price. The licensed body is part of the appeal but also means replacement shells are more expensive than the Big Rock's generic body.

Parts support is strong for both through their respective parent companies, Horizon Hobby for Arrma and Losi. Online communities for both trucks are active and helpful, with plenty of modification guides and troubleshooting resources available.

The Big Rock is the sensible buy for general RC fun. It's faster, cheaper, waterproof, and does everything well. The LMT Son-uva Digger is the emotional buy for monster jam fans who want that specific stunt experience. You'll spend more time grinning with the LMT at the bash spot, but you'll spend more money getting there and keeping it running.