Gustavo,
I do have Enterprise Mathematica, and I have built several Enterprise CDF apps.
My problem is when I want to interface existing commercial tools with Mathematica. For instance, call Mathematica from CAD tools, to add special functionality to them, as add-ins. This means calling the kernel, without passing through the CDF interface (unless someone can explain me how to do it in another way).
The call scheme/trigger is limited to the way these tools are built. A tool that everybody knows about, and so, that is easy to use as an example, is MS Excel. Imagine that I want to add a user defined function (UDF) to it, and that the user enters it in the cells, as many times as he wants. There's no way of gathering in a single call all refreshes that Excel requires when the main calculation loop is triggered (when a user changes a cell that triggers an update). If there are 1000 uses of the UDF, this mean we will call the kernel or the cloud 1000 times. On a CAD system, it is exactly the same thing. Lets suppose that some intelligence is added to each drawn line. For instance, the colour of the line depends on its vertices xy coordinates. Each time we move a line, Mathematica is called to determine the line new colours. If I move 1000 lines at a single moment, the computation will be called 1000 times (since this would be at the single line object level: on a on update triggering event, or something similar).
This means that only local computations are fast enough (if not, the interface of these tools will freeze; and I cannot re-program multi-million hours of commercial tools development, just to optimize the way I can call a cloud environment). Also, some engineering is done off site, at remote locations that don't even have internet access... But this means that we need a full mathematica license for each user, although some sites can be managed with a Mathematica license server.
But since these are not rocket science algorithms, they certainly don't deserve this full Mathematica capability cost, on computers that will never open the Mathematica Interface anyway (exactly for the same reason that the player pro doesn't cost the Mathematica full license: these are calls to pre-built functions, and not reprogrammable by the plug-in user).
We could go for our own webMathematica server, that I imagine could reduce the call time, but this starts to become an IT project, when compared with what could be a simple add-in programmed by the engineer implementation.
We can see on WR site that some kind of Engine is coming out. Although the site, and discussions that I had with more knowledgeable people, makes me believe that this is for bigger projects (that include commercial software distribution, etc) and not really for the day to day need of an engineering office (for which, the player concept is simple). But if a future Engine product is going to exist, why not use the player as one of the forms of engine distribution? If it is a question of license, why not have an extra/specific activation for it? Player, Player Pro, Player Engine? If I pay for an Enterprise version, should this bring benefits on using an engine? Should I be able to call an engine, limited that I only call functions declared on an Enterprise signed package (loaded on init, or something like that)? Isn't this the concept of the Player Pro: as long as the programming is locked, the full license is not needed, and you can use either the pro, or the non pro but with an Enterprised signed version of the program?
Of course I know that someone could just rename all functions, and sign the package... but if we are afraid of license disrespecting, there would be no need to go to all that trouble anyway. The signed notion also means that it is at least slightly traceable. And if it is to connect to other tools, on a production environment, we are probably not on the most prone to illegitimate activity environment. And the competition has been allowing kernel access, through their MCR, for a long time (much longer than the Player has been around), and after all this time they still do it (and to my knowledge, for FREE, that means, simple Player level equivalent). And, in my opinion, at this moment the balance is still short on the exposure side (although some improvements have been made, since the initial launch when we all had to pass though an internet signing site...).
Well, I've been asking for this for the last 5 years. If it isn't there now, it is not going to be there in the near future. Meanwhile, I've been using more and more of .NET..., and less and less of Mathematica (I even almost dropped the Enterprise extra on my last license update, although a last minute hope made me keep it for one more year... but I did terminate another license we had, for lack of believe on WR strategy for the engineering market, where it would have to play along with all sorts of existing tools, and facilitate integration).