@mrcb would be wise to heed the opinion of this post.
The worst part of the ASK, IMO, is the price. Once one gets over that, it is the best option (again IMO) for the reasons that
@zhenya cite. I too have had many types of keyboards for iPads... including the keyboard dock that Apple made for the iPad 1. They were all adequate for the task but not preferable.
With the ASK, it really does feel like an extension of the iPad, not yet another device that needs to be "cared" for. The 12.9 version is a joy to type on and has replaced the Surface TypeCover as my favorite keyboard for a portable device. The greatest challenge was adjusting my typing position and approach because I no longer had to incorporated a cramped touch-typist position due to a keyboard that is confined to the 9.7 screen size of the iPad.
The value of the ease of removing the ASK cannot be overstated. To go from notebook-y type usage to an unencumbered tablet mode so quickly and easily goes a long way towards a converged/hybrid device.