Every time i check the report for any of washington state, swellinfo's rating is completely different than Magicseaweed's. For example, MSW calls for tomorrow at Westport to be 6 ft NW swell at 6 seconds, and no stars at all. Swellinfo says it will be waist to chest high, semi-glassy in the morning and bumpy in the pm.
Whats going on here? If i check magicseaweed against the NOAH forecast, its pretty consistent, yet swellinfo isnt even close. I like swellinfo but the reports have just been completely inaccurate for a long time.
Suffice to say, nothing beats "eyes-on" the swell for determining a forecast's accuracy, that and of course actually getting into the water up close and personal. While everybody is getting their information from the source, NOAA, all interpretations (including who happens to be on at NOAA) are at least partially subjective.
If I were you, I'd set up a test system covering at least a month's worth of waves (not easy I know) wherein you print out the various forecasts and then eyeball it, or surf it for yourself. That's the best possible way to determine who you really want to believe. After all, it's still the weather and people have been trying to make accurate predictions since the beginning of time. For my money (remember it's completely free) Swell Info is at least as good if not better than the rest, most likely because he gets in the water pretty regularly. That should count for something.