I went with heavies in the black and silver milled finish (which look fantastic on the bike!). There's only a couple of ounces separating the standard and heavy sizes (according to the folks at Throttlemeister), so why not get that extra bit of vibration damping by going with the heavier set? (Matter of fact, it was their recommendation that I go with the heavies.) Installed, the added weight certainly doesn't noticeably affect the bike's handling/steering in any way.
Expectation management notice: the Throttlemeister works as advertised (providing that you've adjusted the throttle side correctly at install), but as with all friction/mechanical "cruise controls" regardless of price, they're really only useful on smooth, flat roadways. We do not, fortunately, have many of those roads here west of the Cascades, so I engage the Throttlemester only periodically to give my hand and wrist a rest on longer rides and only when road conditions are conducive to its use (which means for about 5 - 10 minutes at a stretch).