Is it that your kitchen is awash with onions or that you suspect them of being remarkably trecherous vegetables? ie P(onion) or P(cut¦onion)? Either way a gadget would be good. If the former, though, throughput and convenience might be good criteria to ensure the gadget isn't abandoned, if the latter, the most cunning might be best sought, even if inconvenient?

I meant the latter: onions seem particularly prone to these sorts of slippages.

I've always found onion-chopping to be especially annoying and tedious, so I'd guess it's unlikely that I'd abandon a gadget once I had it – it really wouldn't take much for it to be easier than the alternative! It's the activation energy to choose and buy one that I mostly need :-)