Chris Peeples from Vixen Hill Cedar Shutters likes to remind people of the real function of shutters on a house. This helps his customers make better informed decisions about which shutters to order, especially when trying to make their building look historically accurate.
Solid shutter downstairs and louvered shutters on windows upstairs is the proper setup. That's because the solid shutters provided privacy against prying eyes ... perhaps wild Indians too! Upper louvered shutters allowed air circulation so mold and mildew don't grow on walls and other surfaces. The lower solid shutters traditionally had "horns" or protrusions of the vertical shutter styles on the bottoms to allow air to enter under the shutters. This helped with circulation.
Consider sending your expensive wooden shutters back to the factory to be rehabbed to nearly new specs. Do it when that time comes that they need attention. Simply slide them off their pintles. Record on paper and on the back of the shutter which window they were removed from. Unscrew all the hardware and put it in a box. The shutters are now ready to be picked up or shipped back to the factory to be made-like-new. Send the hardware too if you'd like it cleaned and repainted.
Not all manufacturers offer this service but some (Vixen Hill Cedar Shutters in Pennsylvania) offer this service from December through March when they're less busy and have the time. Though not advertised it never hurts to ask about rehab and can certainly can be worth it, especially when shutters are ten to twenty years old. And, if a shutter is in really bad shape, the factory can easily make replacements.
In some cases, companies will even rehab shutters from other companies provided they are similar in design. Start by called Vixen Hill for a comparison with other shutter manufacturers. Start making plans now. Your shutters will be least missed during the Winter and they can be rehabbed more quickly if they're put into the manufacturer's schedule.