"Incorporated into Christ by Baptism, the person baptized is configured to Christ." (CCC 1272)

Baptism configures to Christ. Once configured, one cannot become 'more configured' by another sacrament. Once pregnant, one cannot become 'more' pregnant. 

"configured to Christ the priest in such a way that they are able to act in the person of Christ the head" (CCC 1563)

In ordination the priests is configured to act 'in persona Chrsitie', in the community gathered in prayer, because in fact it is Christ who is praying in and with the community (not the priest personally). In this sense, the 'special character' received is restrictive to specific situations and purpose. Note the contrast with the prayer of the unordained: they act/pray in their own names, as individuals configured to Christ. The 'special' dose not mean better, it means different (in this case, restricted). 

In short, there is no difference in degree of holiness. Nothing can improve on Baptism.