Underworld 4 is the best value!
The overall build quality of the underworld 4 as opposed to cheap ones like the razor and other off name brands, is superb. The hardware is all heavy duty, as is the rear axle. The welds are great and smooth as is the paint. The infinite adjustability of the seat however is where this shines beyond anybody else for certain.
Also, the underworld for comes with a fork ready for discs or rim brakes. The only thing I had to do was order a different front wheel set that had the ability to attach a disc, which is the triad dynasty. We ordered it in green so it'll also give it a little style and individuality instead of being solid black. It was virtually plug and play and makes an infinite difference in the stopping power of this trike! You can either put on a manual disc using the existing brake cable, or you can upgrade to any standard ISO compatible hydraulic brake. While the rear wheels of this are great for drifting, I am looking for an easy swap way to put air filled rubber ones on that I could put on drift sleeves. That would keep some of the noise down to a minimum when you aren't trying to use it for down-hill drifting. All in all this was a fantastic value and ride-minded was a great company to purchase from.