I currently have wood but get fed up with it bowing in the summer.
Even properly installed solid wood can give problems. Generally, in the summer, the air in your house is more humid, as you don’t have the central heating on meaning the relative humidity is the same as outside. Whereas, in winter, the air is dryer – with already kiln-dried wood, it’ll soak in any moisture during the summer and lose it in the winter.
Engineered wood flooring minimises the risk of this happening (while not negating it completely). It also allows the odd “shadow gap” here and there whereas solid timber needs a 10mm-ish gap everywhere. It will need solid wood for thresholds though if you don’t want those shitty pre-made ramps, t-sections, etc. Any dampness problem should always be treated before installing a floor and as a precaution, a 2-part liquid DPM painted on to the floor (in the case of concrete, whether there’s a DPM in the base or not) is never a bad idea.
As with everything, there are good and bad engineered timbers – they differ mainly in the quality of the ply backing (which is 2/3 – 3/4 of the thickness of the board) but also in the quality of the oak and finishes used during manufacture. It’s such a competitive market these days that generally, you tend to get what you pay for.