Take a look at the pics I found on the net below and let us know what you think.

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For comparison here is the ForgeWorld upgrade -

You can't really tell from the pictures I found but the connecting arms on the pics in Planet Strike are bent at about a 45 degree angle at one point and the Forge World kit looks like it is straight. The actual Rolla part is also quite a bit different in each picture.
Be sure to take a look for yourself next time you are at your local game shop and let us know what you think!