I chose to install them on mine, largely because there was significant anecdotal evidence in the forums that people in similar-performance aircraft had had issues with interference which were alleviated when wicks were added.
The particular parts I choose will allow the wicks to be removable, leaving very little visible or aerodynamic change to the airframe, so I will be able to test performance with and without the wicks. The total weight of additional components I'm adding to the build I would estimate at around 0.5 pounds, so the weight argument is essentially moot. There is a bit of additional labor getting the added nutplates and stiffeners fabricated and installed, but it really hasn't been significant at all thus far. The wingtips will probably be the most difficult part, and I'm coming up on that bit soon; everything else has been trivial from an effort standpoint. I definitely spent more time looking through the arguments for and against wicks and planning my install than I did actually performing the modifications as I built. As for cost, other than the wicks themselves I'm probably looking at about $10 in additional hardware. The wicks I'm using are pricey at ~$42 each, for a total cost of $504. There are cheaper alternatives out there; I went with these because they supported the easy-removal option that I wanted.
Here's what I've done thus far:
http://www.mouser.org/projects/rv-10/staticwicks.html
There is a link near the top of that page to Dayton-Granger's recommended installation positions for wicks in the RV-10.
My advice to you is to weigh the risk for yourself, and ignore the blowhards. If you choose to install them, it can be done easily, cheaply, and quickly. If you don't, and you don't fly a lot of IFR, the evidence seems to suggest that your risk of a problem is quite low.