Depth is not gauged by using a particular timing. It's determined mostly by coil size and using the the most aggressive timing that the ground you're working will allow. General rule of thumb, Sensitive Extra will give you greater depth than Enhance, and Fine Gold timing in my opinion is a half way timing between the two.
For depth I stick to Sens Extra, if the ground is too noisy for this setting I'll use Fine Gold, and if still too unstable I'll switch to Enhance. If you want big gold deep, use big coils... 14" and 16" are in my opinion the best size as they still have good sensitivity on small gold as well.
If you go down to 11" and under coils you will get more of the sub grammers, which are the bread and butter options you need to keep the interest up, but will limit your chances on the larger, deeper stuff.
Timings are only as good as the prevailing conditions allow, and matching the timings with the other settings to gain maximum sensitivity in that timing, is what you need to achieve. Gain, Stabilizer and audio settings, including using boost with diminished stabilizer settings can have a dramatic effect on penetration depth, and signal clarity of the deeper targets.
Experimenting on the fields you visit, in preference to using other peoples advised timings will get you to your maximum depths far sooner, and vastly speed up the learning curve, including your ability to get the most out of your machine
Wal