Not too much, in all honesty: more just areas for improvement than dislikes!
It is unfortunate that the interoperability with SketchUp lessened after Trimble bought the 3D modelling software from Google. OpenStreetMap still works fine in this respect, but the synergy between the two programs has stagnated here for 10 or so years: one cannot help but think that this would have improved significantly were the whole suite still owned by the same company.
The inconsistency in the age of Street View data from one street to the next could get frustrating. Some areas look to have been updated several times a year, some not for several years, some have no Street View data at all, which hardly seems insurmountable when one thinks of how long the mapping has been taking place for.
Again, for architectural use, it is possible to use the imagery and the height point data to construct site models, but it would be ideal to be able to export the 3D building terrain data to a format useable by 3D modelling software. Appreciated, with all the companies involved, this would be asking a lot (especially for a free piece of software), but this is more of a wish-list item than a gripe. Review collected by and hosted on G2.com.