Wow, something i never knew... The "strength" of it now make a lot more sense when i was relying on 2 of them to hold my 3.75m ship design.... Thing is, as per the example video above, is that even 1.25m Rockets, attached with 1.25m ports to other 1.25m "pushing" rockets will be "floppy" compared to the same design where both ports are replaced with 2 Structural Fuselage for example. Now having any of the new ports with the strength of a Structural Fuselage might be seen as "OP" though, but i could easily see and exponential growth in Strength: 0.625 ports are very weak 1.25 ports have the strength of Girders 3.75 or 5m ports have the strength of Fuel tanks/Structural Fuselage (I seems to me they are the same?) This is also just comments if you're considering going down the ports route. I'm quite happy building pull-rocket trains or Multi-port Docking You might want to have a look at this mod then: http://forum.kerbalspaceprogram.com/threads/73005-Kip-Engineering-If-you-use-the-hubs-read-the-PSA-%2820th-Oct-2014%29 It seems doable, but as with KW, i have no idea if this one is also what to expect... Haven't tried this mod.