I just finished Ranger school and jump school. I haven't flown since September and am lucky that I will start again on Monday. Every day I was in Ranger school I thought to myself, what the eff am I doing. I could be in Hawaii flying alongside my girlfriend.
Anyway, my mom died while I was in pre ranger and my girlfriend left me while I was in mountain phase. I didn't fly for 9 months because of going. But, even after all that, I am glad I did it. I learned a lot about myself. If you get the opportunity you should take it, though like was said earlier it won't help you deploy any faster.
I also learned that going to Ranger school doesn't make you a Ranger in a lot of people's eyes. It is merely a school that makes you Ranger qualified when and if you finish. The real "Rangers" are in Ranger Bns that deploy a few times a year. They are not all Ranger qualified though. Let me know if you have any questions about it. As to your original question, there is never a good time to go to Ranger school. It always sucks. The industry will do what it will do, and you can either take a job now or later. I think the real question is do you want to put everything else on hold for a significant commitment to something totally different than an aviation job. That is a decision I made and I lost a lot of important things, namely a girlfriend and flight time/flying skills that I am now trying to regain. But, in the long term, those things can be recovered. A tab is forever.
Hope that insight helps.