Bought for use in a Fender '68 Custom Princeton Reverb Reissue. Previously tried the Celestion Ten-30 (stock), a Jensen C10R and a Jensen P10R with little success. After some research found this Jensen P10R-F and without out a doubt this is the perfect speaker for this amp.
Pros
Very balanced, Fender-like chime. Good bass response and a perfect crunch sound when over driving the speaker (volume over 5 and upwards). Excellent note seperation and response when riding the guitar volume. Reverb and Tremelo also has a more 3D and fuller output than I experienced with the other speakers. It also brought out the woody sound of the neck pickups. Finally, no icepick trebles or bass fart out, as was experienced with other speaker selections.
Tested with Fender Stratocaster - 54 pickups, Gibson Les Paul Trad. - 59 pickups.
Cons
None that I can think of. As this speaker gets more broken in I can only assume it will improve even more in tone and response.
Summary
A great speaker to tame the the icepick treble and farty bass that can often be found in the PRRI. Lovely overdriven speaker crunch. Works exactly as it should straight out the box!