Hi Tom and Barry,
The Bean Streamlight rods are fairly stout: the 12'6" for a #7 is a #7/8; the 13' for #8 is an #8/9; the 14' for #9 is a #9/10. The rods that I tested were lined with the S.A. Short Head in the above line designations. During my overhead test casts, the rods threw the entire S.A. lines with the backing knot to the second stripping guide.
In my opinion, a two-handed rod does not know the difference between a load placed on it by a Spey cast or a load placed on it by an overhead cast. Any rod has a reasonably optimum bend profile; it is up to the caster to discover that profile and adapt his/her technique to accomodate the physical characteristics of that profile.
Personally, I love the Loop Yellow rods for overhead casting. It is a very smooth rod for both Spey casting, Underhand-style casting, or overhead casting. I do cast them a little differently than, say, the CND Atlantis or the G. Loomis Stinger GLXs. This is as it should be: it is all a matter of subtly adapting one's default casting stroke to suit the requirements of a new rod in hand. Even the old Sage 9140-4 'brownie', not considered an ideal overhead rod by most standards, can absolutely bomb overhead casts in the right hands.
For my purposes, the L.L. Bean Streamlight 13' #8/9 wt. is the most versatile rod in the series. It has the length and the authority to handle longer casts and a good push of water, but is not so long that it will be cumbersome on smaller streams.
Tight loops, TB