Getting this beast for free is good, when the price for each is about 400 bucks (initially was 600).
The ruggedness of this transistor is better compared to the counterparts from Freescale. The PCB recommended by NXP should be fine, I've seen once an working FM broadcast PA with this transistor using the recommended layout. I never seen an HF application with this transistor.
**broken link removed**
At this high output power level very important is to follow strictly their recommendations for PCB material, mounting, soldering, and quality of components, which sometimes are hard to get.
On the other hand, the gain of this power transistor is higher than usual PA's, which makes things more complicated in terms of self-oscillations which can damage the transistor.
Anyway, you mentioned that you got "few" of them...so you have some room for mistakes...