as it says really pros and cons, both about 300 miles use either significantly better or lighter and ust go best looking one

ta

IIRC FSA gossamer is a complete misnomer – they really are not very light – ultegra SL perhaps 100g lighter.

SL cranks look great when new but scuff easily (I have read).

Used to be the case you could pick up s/h new/unused FSA gossamer cranks really cheap I assume either because they were sold pretty much everywhere online at big discounts or people took them off stock bikes asap.

Can't comment on the Ultegra's, but I've had a FSA Gossamer on a Tourer and it's been absolutely fine. Cheap and functional. Not too heavy either (if that sort of weight issue really bothers you).

I've also got one with a 46/36t on my back-up CX bike (CRC were selling them NEW for £39.99 a little while back). Again, faultless.