A recent blog post by Peter Todd shows how all of the wallets tested do not even warn users about a potential double-spend, but most of them also fail at warning WHEN a double-spend has happened. This is an unacceptable scenario for the Bitcoin ecosystem in its current stage, as users have little to no protection when it comes to using some of the most common wallets. With the recent addition of opt-in replace-by-fee, it seems wallet developers have not taken the potential repercussions into account.
http://bitcoinist.net/bitcoin-wallets-vulnerable-to-opt-in-replace-by-fee-double-spend-attacks/
