My X-Fi Forte, while I still had it (later traded for a Titanium HD), didn't totally crap out on me...but it was bought in March 2011 and had a heatsink on the EMU20k2 DSP, which earlier Forte cards don't. It could suggest a later batch that's not nearly as prone to failure.
As for the built-in headphone amp thing, while it's nice to have, it's important to ask whether you prefer to match your headphones to the amp, or match your amp to the headphones. If you do the latter (like I would think most people would), then chances are you'll have to go external at some point, unless the headphone is so sensitive and impedance-matches well enough with most equipment that it needs no dedicated amplifier. (The AD700 is one such headphone; not as certain about other popular, easy-to-drive models like the AD900.)
Also note that on either of those cards, if you're going to be plugging your headphones straight in, I urge you to start at only 5% volume and work your way up. It won't be much past 7% (at least with an AD700) before the volume becomes painfully loud. (If you use an external amp, keep it at around 10% to 25%. This should eliminate any possibility of clipping and give you more headroom with the EQ.)
