In all seriousness, here's my take on it. Take it for what it's worth...nothing. To PFT or not? The rational side says "what's the difference"? You pay for the training either way. From that perspective, there is no difference, 250 hours of turbine multi is good good good. Do you need Turbine Multi for the first job? That's a matter of debate, I tend to think that you don't. In the beginning, Multi is Multi. The 121 side of it, well, that's worth its weight in gold. So there are some definate positives.
The problem with PFT is that by supporting a program like Gulfstream's, you support a company that has eliminated one paid FO position per flight. You thereby hurt the group of pilots that are near the magical minimum of flight time that would allow them to get a job where they are paid to fly an airplane. (Remember, it only takes 1 job opening to fulfill your dream.) That pisses this group of pilots off.
While the retired Captain tells you to PFT, he/she is not going to be the one down the road that is interviewing you and hiring you for the next great gig. I will be the one interviewing you. If you jump ahead of me now, it won't make me mad. But down the road, you never know what breaks I might get. Perhaps I jump ahead of you and get lucky at the next great gig. I can tell you one thing for absolute certain. WHEN I GET TO THE POINT WHERE I AM AN INTERVIEWING CAPTAIN, IF I SEE GULSTREAM ON YOUR RESUME, YOU ARE NOT GOING TO GET THE JOB! It only takes one negative in the interview process and "Thanks for applying with XYZ, unfortunately we cannot offer you a job at this time. Please try again in 6 months."
That's where the rub comes in. You are going to have to depend on your fellow pilots for jobs, now and in the future. Even if 90% of those pilots don't care whether you PFT or not, 10% of them might. The interview process is stressful enough, why stack the odds further against yourself when all you had to do what go about it in a manner that isn't as controversial? It's your future, not mine.
Good luck, hope this helps. And so you know, I made the same 'later in life' choice and started at the age of 32. Time is time at this point, the 250 hours you get can be had for a lot less. There aren't many places that are going to hire you after 250 hours in the Gulfstream program. Sure it's valuable, but I say purchase some major bulk time if you're willing to pay for and fly your pants off. Get a 1000 or so, maybe buy 300 multi from Ari Ben or something (for half the price of GSI) and get on with your training.