From the docs:

    1.2 Features of VCL
    ∙ Vectors of 8-, 16-, 32- and 64-bit integers, signed and unsigned
    ∙ Vectors of single and double precision floating point numbers
    ∙ Total vector size 128, 256, or 512 bits
    ∙ Defines almost all common operators
    ∙ Boolean operations and branches on vector elements
    ∙ Many arithmetic functions
    ∙ Standard mathematical functions
    ∙ Permute, blend, gather, scatter, and table look-up functions
    ∙ Fast integer division
    ∙ Can build code for different instruction sets from the same source code
    ∙ CPU dispatching to utilize higher instruction sets when available
    ∙ Uses metaprogramming to find the optimal implementation for the selected instruction set and parameter values of a given operator or function
    ∙ Includes extra add-on packages for special purposes and applications

(Tldr: this is for CPU vectors and isn't directly comparable to a linear algebra library like Eigen.)