
From what I see, the "best of the two" depends on which target they are or will be used against.
For example:
- Against moving targets during bad weather (such as dense fog) or other obscurants, the SPEAR should definitely be better due to the MMW radar seeker.
- For high precision strikes against static targets (for example, hitting a specific point of the static target such as a window) located far or very far away (long range) the SPICE-250ER would be better due to its EO seeker together with the pre-loaded target imagery.
In order for the SPEAR to have the same high precision strike ability against static targets the launching aircraft must be much closer to the target which would then 'paint' the target's "point of interest" using Laser aimed by a TGP (or internal EOTS in the case of the F-35).
As such I would give a slight edge to SPEAR mostly due to the MMW radar seeker which together with the Laser seeker seems to give the capability to somehow be able to engage a larger variety of targets.