I don’t have the Pro40 or the InsideOut, but I have the Womanizer Premium and love it and recommend it (and it’s waterproof). Right now the Womanizer Premium is 40% off on the US and the UK shopping sites, so it’s at a price comparable to the Pro40. Also thought I’d pop in a link to a suction toy comparison table 
in case you’re still browsing! That thread has some good womanizer advice and recommendations as well 
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