cannondale synapse 2 or 1000

I am trying to decide on the cannondale alum. synapse 2 or the cannondale CADD 8 1000. The synapse has 105-ultegra 10 speed groupo and the 1000 has full ultegra 10 speed. Synapse has shimano 550 wheels and the 1000 has ksyrium equipe wheels. The synapse i can afford now @ 1599.00 and the 1000 i would have to wait for about 3 months and it is 1899.00. Do you think the 1000 is worth the difference.

I have the Caad 8 1000 and love it, i have put approx 2000km on it and am yet to find any problems with it at all. The ulotegra 10 speed shift is always swift and relyable and the frame seems to absorb alot more than I`was led to believe an aluminium cannondale bike would