But never ran a ranger in any edition, much less this one....
Probably just as well, the class was purely martial at that point, so you'd be un-learning the basic concept had you played prior-ed rangers.
The PH1-only TWF Ranger is pretty limited, even for a Striker (I'd be bored to tears with it in a matter of minutes, myself, not caring for strikers in the first place). It's probably the second-simplest PC option to play in the PH1, after the archery ranger - if you're an experienced player, even if not that experienced with 4e, you might find there are more interesting options for you, and maybe leave the strikers to the newbs. The Wizard, for instance, is more challenging and engaging, as are either of the Leader classes (and they're /not/ heal-bots).
That said, as I recall, the early PH1 TWF Ranger ran into problems maintaining AC, because of the need for DEX for AC, STR for attack and WIS to support riders. Since you used random stat generation, you've dodged that bullet for now, you'll likely be Paragon before you start noticing the symptoms of MAD.
DMS house rule. A lot of the players are new to gaming as well. Almost convinced him to run 5e, but he knows 4e better.
Much as I like to encourage support for the current ed, running it after getting used to 4e is a challenge (quadruplely so if you started with 4e), and it is a steeper learning curve for new-to-gaming players. So probably a good call on his part.
I assume from the double-sword preference that you come to 5e with a healthy appreciation of 3e?
Mechanically, a double-sword is nothing for the DM to whinge over in the hands of a TWF ranger. You could just use a pair of longswords, anyway.
Anyway, PH1-only limits you, but if he's not using errata, it also opens up some crazy. MC to fighter and going Pit Fighter at Paragon, for instance. And unerrata'd 'Blade Cascade,' I think it was...