As we tow boats around the country to events we've never dared go for trailers that are not tried and tested so we have largely stuck with usual brands. Over the years we've had;
- De Graff (x2)
- Indespension (x2)
- RM Trailer (x1)
- Rapide (x1)
- SBS (x1)
Never had an Extreme so can't add any details on them really. They do seem to be competitively priced from what I've seen at shows and they do appear to be the "newcomer" to the scene.
The De Graff trailers were very good as was the after sales. Some surface rust appeared on the suspension units but that was all. Very adjustable and very well built. We've have had (I think) 1.9 and 2.8 tonne versions over the years.
Indespension were very good and easy to load. No manufacturing defects but again the suspension units rusted and the brake pad lining came away from the brake pad
but this is more a component issue rather than a manufacturer
The RM Trailer was secondhand and for Thundercat. Basically it was battered when we got it and we replaced everything on it. Seemed OK after that!
The Rapide was under a Ribcraft 585 and we sold it as it was at the end of its life. We got a new SBS with sealed bearings that I was a bit worried about but touch wood it's been 100% and we are doing serious mileage with it. After sales is also good and the team helpful. We were advised to always wait after towing to let bearings cool down before towing on the SBS with the sealed bearings. This seems to have worked as they are holding steady.
Personally given your choice of SBS or Extreme I would go for the SBS due to lack of info on the Extreme and a good experience with the SBS
Chris