Both should be an option within APT with additional option of some animated text or flashing graphic/arrow on the bar which can read "click here for thumbnails" so if the bar shows by default & then slides back after few second the user would still know & can the animated text, if the bar is off by default same is applicable to it.
Thumbnail scrolling is a very much required feature specially when you have more than 10-12 images in a tour. BY providing scrolling we can exactly set size of thumbnails we want.
I agree will all of the above comments.
Brian - http://PhotoWebLab.zenfolio.com
Nikon D600, D300, Nikkor 10.5mm, Sigma 15mm, Sigma 10-20mm, Nikkor 18-70mm, Nikkor 24-85mm VR,
Nikkor 50mm f/1.8, Nikkor 55-200mm VR, Tokina 80-400mm, AutoMate, Nodal Ninja 3 Mk II with RD-16, Nodal Ninja RD1
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