the main advantage with a PM account is the calculation of margin impact of each position - by actual delta. If you have a reg T account, each call you sell is essential viewed as having a 1.0 delta. What I mean by this is it matters not how FOTM the call is, the broker automatically assumes that it is equally likely to get ITM as a 100C; it will hold an entire 100s lot as collateral for it. A PM account looks at the actual delta. So, if you sell a 0.15 delta call, you can use 100s as collateral for 6 of those suckers. As the calls get closer to expiration their delta goes down which frees up more margin. So what happens if you have a few calls totaling 0.4 delta that you dont like, given the current momentum? You can roll them out 3 months for $0, decreasing their delta to maybe 0.25. Now, you have 0.75 left. You just gave yourself a second chance to observe the price action. You can then sell a second rounds of weeklies from a more advatageous entry.
*This is oversimplifying the calculation for the sake explaining the concept. A lot more go into the calculation: expected move, IV, all the greeks, etc… the primary idea is still the same: the more calls you sell, the closer to itm they are, the more volatile the stock is, the more collateral it will cost you.
Same goes for puts. The lower the put strike is, the less collateral it requires. Im especially fond of naked puts because for the same premium, I can sell naked puts at a lower strike than the short leg of a BCS. Sure, I dont have the protection of the long legs but thats the cost Im willing to pay. You can look at a few examples to see how much safer naked puts are compared to a bcs.
To sum it up: PM takes the training wheels off and you are able to take full advantage of your positions, be it cash or long stocks. However, its just a tool. It can backfire big time if you dont respect the risks.