If you can afford it, I'd make the switch.

You're lucky. You have options. You can switch rim diameters, brake caliper lengths and use/not use drop bolts to get a set up that works.

The only reason to switch to 700c would be to increase your tire and rim options. That is a compelling reason but not manadatory.

One cool (but admittedly trivial) thing about 700c clinchers is you can swap between wheels with tubular tires with no additional changes.