I haven't had issues with Alacrity causing me to use Force faster. In fact, it gets my heals "off" faster which gives me more breathing room. I tend to spend more time not casting because of the Alacrity. That said, I'll be looking for Crit/Surge to replace it when possible, but I'm not going to stick with lower gear just to cleave to this bizarre idea that having Alacrity will somehow force me to run out of Force.
I'm not really sure about other healing classes. My problems with Alacrity are referring to Operative healing only, since we have one spell which is affected by it, two if you count Kolto Infusion. If it added HoT ticks or reduced the GCD on instant-cast spells, then it would be a *lot* more useful. As it stands, it's a subpar stat.