I debated this issue recently with a few lifters who use a big arch (one benches 205kg at 83kg, so fair enough, but the others seemed to think his technique would suit them too, and I wasn't so sure). I feel it's not worth it, as the risk of long-term damage is too great, but they disagree, saying it's important to build up gradually (they also believe in working up to using max-legal grip width, which I also disagree with, lol!)
I really feel that a slight arch and a strong setup otherwise is best as I've suffered from serious back problems related to this in the past, and I feel that the small decrease in RoM isn't worth it. However, if you're competing at a high level and you find that it doesn't cause you problems, I don't think you need to change. If you don't know, err on the side of caution and arch moderately; if you're experienced and like to arch "excessively", go ahead. Only you know what your back can tolerate.
Remember, many of the best benchers in the world don't arch very much - especially in heavier weightclasses. It's down to personal choice, but a lack of arch is not what's preventing you from benching to elite standard. It really isn't.