While I don't know the technical differences between the desktop and laptop versions, I in fact have almost the exact same card (a 7690M XT) and I have been using the MOBILITY beta drivers for a long time with good results.
The only "but" i find, is that sometimes (i.e. changing from X beta version to Y) the Catalyst Control Center (CCC)doesn't work properly, thus not allowing you to manually choose what graphic card to use for each applicaton (or game).
For those who don't know:
Most laptops with dedicated GPUs (at least AMD cards), have an "hybrid" option, in which by default, the dedicated GPU only is used if the app really needs it (e.g. most of games, or other demanding apps). The Catalyst Control Center (CCC) lets you manually override such option for different apps, so you may choose to use the dedicated GPU for simpler games/apps that may need more performance, or the other way around.
In my particular case, despite CCC not "woring" per se, I've had no problem at all when using games. I do use my laptop for all kinds of games, from simple, to current, demanding games, like Tomb Raider, Batman AA/AC, etc just to mention some.
If I'd stayed with the official drivers of my laptops manufacturer (HP), I would DEFINITELY not have as good performance as I do with up to date beta drivers. I've only ocationally had problems wiht one or two versions, in which some games crash, but it gets fixed by just installing another newer beta verson of the drivers.
At the end of the day, at least in my case (with an HP dv6-6c85la laptop) It is perfectly safe to use official beta drivers. Just be sure for them to be the Mobility versions, because they are somehow optimised for the mobile versions of GPUs. One time I tried the "desktop" version of the drivers, and they simply refused to install...
And just one final note, be aware that your GPU description, on windows device manager info dialog, may change from your 7650M to something like "6700 series". That is because the 7650M is just a designation from laptop manufacturers, but "internally" it is just a modified 67xx card. See here http://www.notebookcheck.org/AMD-Radeon-HD-7690M-XT.74106.0.html for more info regarding that.
I hope that, despite not a direct answer, I helped you =)