Quite a complex question, spring build up is usually far better in poly hives than wood, but the full rationale why is complex.
Bees in poly/insulated hives overwinter using far less stores than those in un-insulated. Suggesting they don't do as much work in generating heat; perhaps meaning many more of these long lived winter bees are not shagged out by spring and may live even longer (this is speculation on my part, but not unreasonable). I generally find far less dead bees on the mesh floors come spring (although this might be tempered by the number of undertaker bees per hive. But generally I think more survive and are fitter, which helps kick start the spring build up. Nectar is less important if there are stores, but pollen or it's equivalent are essential for rapid spring build up (add in extra complications of area where you live/spring weather conditions and distance to nearest available pollen sources)
The lower heat loss from poly means less bees are needed to maintain brood temperatures and hence (assuming queen is up to it) she can lay more brood early. So an equivalent sized colony in poly can maintain brood heat over a greater area than one in wood, which helps kick start the colony spring increase. There are also more early season foragers to get things off to a flying start.
When I compared similar sized colonies in poly alongside wood my first inspections showed that those in poly where miles ahead. Notes from 6-7 years back show those in wood by April where on 2-3 frames of brood whereas those in poly where on 6-7.
I know others who have done similar comparisons have found similar results.
There are probably other complex parts to this equation.