The tradeoff between presale tickets and guest lists is that signing up for the guest list may be cheaper than buying presale tickets. That being said, there’s NO GUARANTEE you will get in through any guest list. Venue management can decide to close the guest list at their discretion and without warning at any time, once their capacity is reached. Also, the line for guest list is usually much longer and moves much slower than the line for presale tickets.
With a presale ticket, you are guaranteed to get in, and you advance to the front via a shorter and faster line. You may have paid more than someone who got in on guest list, but you are assured of entry in a timely fashion. Some clubs offer girls guest list only and some do not even offer a guest list on days of high demand. In those situations a presale ticket must be bought, or else a table reservation made, to gain entry.