Humboldt County's Own products are awesome. I use quite a few of them and find them to be a quality trustworthy company.
Haven't ever switched nutes mid grow before though, so not sure about the effects on the plants. If you do decide to do it, I would at least suggest trying to match the feeding schedule to your old one in terms of the amount of N-P-K you give them. But again, not really sure. Would be interested to see what happens should you decide to do the switch.