kennyb, you can have the OLD LIONELS!!!, a 736 is one of the few trains that I have ever regret buying.
Obviously you have never operated with command control, if you think that sound is the only thing that the newer trains have over the old. I will take the ease of controlling multiple trains, without the complex and restrictive block wiring needed with the old trains. Oh I also prefer the smoother operation and better details of the newer trains.
If you prefer to spend the time wiring the layout rather than operating it, that's your choice. If you prefer inferior running, infrior detailing and "Lionel Lines" on all your tenders, then the older trains are an EXCELLENT option for YOU.
" Outdated tomorrow" systems, TMCC came out in what 1994, 1996? Legacy is fully backwards compatible, and will operate TMCC perfectly fine. Legacy offers more features, but TMCC is still a viable system. DCS has progressed to Proto 3, but again is fully backwards compatible with PS 2.
This Hobby offers all kinds of choices for everyone, it seems that we have simply made different choices in how we each choose to ENJOY it, niether are RIGHT or WRONG, BETTER or WORSE, just different in how we enjoy our mutual HOBBY.
Doug