IMO, the netcode is visibly improved. Before we started running the latter test patches on the UKCT server (Odd Compo and STCC) we were getting fairly frequent mass disconnects. Now, we're seeing absolutely none.
There are many factors that cause the problems that you're experiencing, and very few of them are within the control of Scawen's coding or, for that matter, the server that the game is hosted on.
Most notable among these are the new policies of many ISPs, involving traffic shaping. In the UK, for example, seemingly the worst of all ISPs for this is PlusNet. Anyone on PlusNet in the UK is pretty well stuffed as far as LFS is concerned. They're also stuffed as far as Limewire/Emule/BitTorrent is concerned, and it's the ISP's attempts to kill their P2P traffic that is actually causing the problems with their clients' gaming on LFS. As a result, PlusNet customers are often suffering disconnects, server lag and disproportionately big crashes when sharing paintwork.
PlusNet is just the worst example, but all UK ISPs are now habitually shaping traffic - even the cream of the crop, NTL/Telewest cable, is now shaping traffic during peak times. ISPs are generally disparaging of P2P traffic, and because LFS servers typically use ports which are usually used by BitTorrents and other P2P applications, the LFS packets are mistaken for P2P traffic and the priority for those packets are artificially manipulated by the ISP, delaying them and often just discarding them.
I only know specifics about UK ISPs, but I'd be surprised if the attitude that UK ISPs have isn't reflected in ISPs around most of the world. If you think that there is no way that your ISP is shaping your LFS gaming packets, rearrange the following three words into a well known phrase or saying: "cloud", "land", "cuckoo".
An additional note about the STCC servers: I'm delighted to observe that the STCC's server is delivering a reasonable ping to users not just in Northern Europe, but in fact as far away as South Africa, where I'm told pings can be as low as 80ms (UK to SA, I think that's brilliant!). We're also not getting bad pings to Singapore, Malaysia and Australasia. As a result, we're getting gamers from a LONG way away. I'm delighted about this and, although on occasion there can be the odd problem with slightly warping cars, it doesn't happen often and the plus of having a truly multinational server far outweighs the occasional skyrocket. I hope you guys agree.