OK, there's been a fair bit of "Abbott bashing" here, not of all of which is either fair or wholly correct.
There's no doubt that they are not as competetive as some other tuners for upgrades, but they do have certain areas of expertise which few others can touch, especially chassis developments which have been born out of successful racing of the C900, NG900, and 9000.
I'd agree that there are others who have better knowledge of remapping Trionic systems but Abbott's basic upgrades do not affect base boost pressure and therefore APC protection except in the case of LPT upgrades when they fit an intercooler, in which case the base boost can be safely (and is) raised to FPT levels. The only "mod" that Abbott sell AFAIK that affects knocking is the Manual Boost Control Valve, which effectively removes the ability of the Trionic system to reduce boost under knock. The system can still detect knock, and will follow the initial response which is to vary the timing (up to a limit) to cope with this but cannot then reduce boost if that dosn't work.
Eric- the feeling is mutual between Abbott and Trent, and it really pi55es me off. Graham's wife has done an awful lot of work as a technical translator for Saab and it is a huge waste that they can't work together. Just for the record, it's my understanding of the history was that it was Trent who broke the "gentlemans agreement" about being agents for Abbott's products.
And Eric, (regrettably) I rather think I'm going to take issue with the statement "My advice: ignore Abbott advice".
OK they're out to sell their stuff; who can blame them; but the one area I would trust them on is chassis and handling- which you also acknowledged yourself. If any supplier is going to recommend a particular product, then they are going to go with what they know best...
IMO Abbott have not fully explored the engine management system to it's maximum potential because of the limits imposed on them by the class of racing they were in. However, you can make a car go a helluva lot quicker in racing by sorting out its handling- which is exactly what they did, as was amply proved by anyone who saw the way their 9000 handled at the track day. Bill and I might have been quicker on the straight, but it left us standing through the corners, and that wasn't just down to the driver...
But in the real world, I reckon just about any combination of lower/stiffer springs and uprated/adjustable dampers is going to provide a worthwhile improvment in handling. Different suppliers might well have matched the characteristics of custom springs to their dampers for optimum performance (which is in effect what Abbott are saying), but as was said earlier, unless you're doing track work, you're unlikely to push things to extremes.