Multiple thoughts on this topic. I'll go objective to subjective.
Financially: the 'bonus' is still 25,000 to 35,000 dollars. It was introduced in the 1990s, yet has not substantially changed since then. in 2015 when I took mine (25,000 for 5 years), it should have been at least 37,000 to account for inflation alone. I didn't do my homework. I recommend others do theirs before deciding. By comparison, if you separate at 12 years of service and join an airline, a part 135 operator (think flying twin otters or -8's in hot places), a cargo carrier, or even a cargo carrier feeder to a major cargo carrier, you will make more money in the following 8 years than you would have in the Air Force.
Moreover, the Air Force continues to insult their pilots with the need for a bonus and the option to take it...and sometimes no bonus at all...while GIVING doctors, surgeons, and dentists professional pay that exceeds the aviation bonus while not requiring a "take"...in the AIR FORCE. Not the dental force, or the medical force, the Air Force. This year, as a reservist pilot, I will not get an aviation bonus because it was not offered to pilots in my air frame at my base, because clearly the air force is good on pilots...while medical professionals get an automatic bump to account for the money they aren't making on the outside. Objectively the USAF demonstrates that it does not value it's pilots and is unwilling to truly push for retention improvements. The fellas at RAND have routinely updated their data that shows retaining a USAF pilot at 12-15 years for another 3 years using a $100,000 per year bonus is more cost effective than producing new pilots. Just like big blue, we'll completely ignore the safety improvements of retaining experienced pilots in one of the most complicated and dangerous corners of the aviation world. No, the USAF simply continues to accept the shackles that congress places on it regarding the restricted pilot bonus instead of pushing HARD for a professional pay similar to the medical career fields. That lack of effort shows me all I need to see.
However that financial analysis ignores the quality of life items, right? Unfortunately a QoL analysis only puts more nails in the coffin. For example, pilots are likely to marry spouses in a like-status, like-education-level, and like-earning potential bracket. In short, we choose to partner within our peer group. Yet the Air Force completely ignores this fact and continues to move us every three years, thereby negating our life partners the opportunity to professionally put down roots and create a career, thereby stifling their earning potential. Yes, the air force has claimed new programs to improve this problem by letting pilot homestead, but they are largely lip service programs that have shown to kill career progression. Take a look at how well the career pilot program went...for the four individuals that got accepted. Or perhaps AFPAK HANDS, which I watched get used as a "force shaping tool" to force 8 senior MAF MWS IPs decide to separate instead of taking that as their next assignment (circa 2016). That trend has not changed.
The senior leaders of the USAF refuse to force the middle leadership to abide by the simple rules of organizational excellence: Train and equip and prepare your people so well that they could leave and be hired by any other organization immediately, and treat them in such a manner that they don't want to.
My own story included an advisory that my last three years before hitting 20 would include a PCS (I'd been in my API-6 'flying' non-flying desk job for 2 years) and a 1 year deployment...because 2.5 years in the desert and 4.5 years total gone from home in 17 years wasn't enough. When I asked for special consideration as the job I was filling is difficult to fill, I was flatly told no. So I voted with my feet. Then the USAF promoted me 3 months before my separation date...and I still separated (promotion carries no ADSC).
But let's shift gears and assume I decided to apply to be commander a staffer or whatever career progression track big blue would advise me to take. The peek behind that curtain reveals nothing but another curtain. I've been close personal friends with enough commanders to have learned that becoming a commander, an aide de camp, or attaining some other advancement position does not actually allow you access to change, fix, or improve the system as we all secretly hope to do if given that opportunity. Instead, you are rewarded with a PCS, school, or lateral move every 1-2 years. Moreover, you get the exposure to discover that the senior GS and SES community as well as the bad O-7s (there are good ones, but the bad ones abuse their influence and tend to poison the well far beyond the abilities of the good ones to fix) and their staff sycophants continue to perpetuate the self-promoting trend of the USAF. That leaves the hard working 'good guy' O-6s and O-7s swimming very much upstream if they want to institute sincere and good changes. I know several of these excellent men and women, and I pray their influence changes the USAF. I realized that fighting that battle was not in my blood, so I couldn't continue on that road.
What's that have to do with the bonus? In short, those who were going to stay would have done so anyways. Those taking it for the money factor only may not have done their homework to realize they could make much more elsewhere. So it's not really a retention bonus, it's a 'thanks for staying, we want to lock you in and take away your power to say "no" pay'.
Hence I say, unless you know you and your family want to stay at the whim of the you-are-nothing-but-a-number AFPC assignment process until the end of whatever commitment you are 'offered', don't take the bonus.