Although the premise first hearing about it and reading it didn't exactly grab me and didn't sound plausible for a minute, the star power did attract me enough to see 'Who Was That Lady' anyway. Also had heard the title song beforehand, sung by none other by Dean Martin, and was quite impressed. Tony Curtis, Dean Martin and Janet Leigh's careers were all hit and miss but they were always likeable enough and always did their best regardless of what was thrown at them.
Which is the case here with 'Who Was That Lady'. Can definitely see why the reviews here are mixed, with some really liking it and others being indifferent. Everybody is not at their finest and did have better material, but it doesn't waste them either. As for me myself, my opinion is somewhere in between, finding enough to enjoy but not really loving it and wishing that it could have been more. With it not starting off all that promisingly but it got better.
The story is very thin at times and is often very implausible and a little more complicated than it needed to be (even for a concocted story between characters intended to be that way). It could have gotten going quicker.
In terms of the writing, 'Who Was That Lady' did in my view at times try too hard for laughs, meaning some of the material is strained. While everything with the Russians is quite fun to watch and suspenseful, the film feels like a different film towards the end. Going from frothy romantic comedy to thriller.
However, the glossy production values are skillfully done. The music has energy and charm and the title song is vintage Martin, which will be a delight if a fan of him (have personally always loved his voice). The direction becomes more at ease when the film gets going and the dialogue has plenty of wit and is very amusing in many parts. The restaurant scene is a joy and very memorable.
Curtis is likeable and has strong comic timing, while over-eager at times. Leigh is charm personified and brings a lot of vitality to a role that's fairly thankless and plot device-like. Martin works very well with Curtis and amuses. The chemistry between Curtis and real-life wife at the time Leigh are sweet without being too sugary, one would not have guessed that they were apparently having marital problems at that point. James Whitmore is enjoyably subtle and Larry Storch steals his scenes even if his character seemed as if it was lifted from another film.
Summing up, quite enjoyable though am a little mixed on what my thoughts are. 6/10