No, because all packets are still sized 512 EU. There are just more of them, and cables do not care about the number of packets. Only the size matters(tm).
As for the initial question, creosote in a boiler gives you 3,200 heat units per bucket, and in a semifluid generator it gives you 3,000 EU per bucket. Since a boiler pretty much always outputs more than 1 MJ per HU (the largest ones can go over 8), and the steam turbine gives you 15,625 EU for every 10,000 MJ, the boiler is by far the better choice even if you only want EU.
However, the boiler + turbine is significantly more expensive to build than the semifluid generator.