As a fellow out-of-field applicant, the post-bac program I did was my application's saving grace. I would highly recommend it if it matches your bigger picture grad school, career, and life goals. If your goal is to get into school now and move along your education and debt doesn't bother you too much, do the 3 year program. If your goal is to reapply to schools and open up more opportunities (either in more desirable locations, from "ranked" programs, or with funding), then do the post-bac. My goals were to pad up my pretty weak CSD resume, get into solid programs, and receive some funding opportunities. I was able to do just that, while working full-time and enjoying the perks of a work/life balance.
Ultimately, a post-bac's strength is that it provides you time... time to develop your resume, time to live life, time to learn about your interests in the field. However, this strength is also a post-bac's weakness... for every year you are spending away from grad school, you are one year further from working as an SLP. There isn't going to be a perfect situation, so you have to pick what's best for you. Below is my personal list of pros and cons from my experience working full-time for 2.5 years while taking post-bac classes part-time for 1.5 years (5 semesters).
Pros of doing my post-bac:
-- learned fundamental CSD material (i.e., it wasn't just a means to get me into school, but it also built up my academic foundation)
-- demonstrated my ability to do well in CSD classes (post-bac GPA 4.0)
-- improved my undergraduate GPA (3.38) to a more competitive overall GPA (3.48)
-- allowed me to work full-time as an RA in an aphasia lab, which not only gave me a salary with insurance and vacation benefits, but it also provided me hundreds of hours of hands-on patient testing experience plus solid LORs that could speak to very specific skills and achievements
-- I took $0 out of savings; I used my company's tuition benefit to pay for the program and some pocket money to pay for books
-- I did an online program, which meant I could do classes on my own time
-- I have life experience between undergrad and grad school... work/life balance is important, and these past 2.5 years being a city yuppie has been the perfect break between my Bachelor's and Master's to refine my life and career goals. I know I will cherish these post-college, city-yuppie years.
-- significantly improved my grad school application results... top programs, funding opportunities, and 7/8 acceptances. I have choices and I will probably graduate with no debt.
-- added 3 years before I can actually be an SLP
-- added 3 years before I can make a more comfortable income; I managed to get by just fine with my RA salary, but not having to budget down to pennies will be nice in my future
-- it's a hustle; don't let the pro list fool you, if you're going to maximize the potential pros of a post-bac, you are going to have to work hard and use your time wisely. I was the only person in my friend group who was taking classes outside of work, so I had to be organized in planning my study schedule and also disciplined to decline certain social opportunities for the sake of getting As. My friends understood and would even join me in coffeeshops and read beside me, but it also sucked to have to turn down certain things and stick my nose in a textbook for a Saturday afternoon. There were times when I would be tired from work and the last thing I wanted to do was write a homework assignment.
-- not quite sure if this is a con or not, but I will be one of the older people in my upcoming grad school cohort. I went to an interview day and felt very "old" compared to the other interviewees I met. In the big picture, I'm not that old, but I have aged away from college life. I will graduate at 28 years old as opposed to 25 years old.
Personal advice: 1) not getting in elsewhere... I think a post-bac will only help you; you were able to get into your two programs with your current resume so I don't think a post-bac will hurt your future applications; 2) your love life... If I were you and very seriously wanted to make your bf/gf a life partner, I would forgo or try to minimize the long-distance dating. Why don't you find a job, live by your partner, do an online post-bac program, then reapply to schools and open up your options to more than just these two? I met, dated, and will be marrying my fiance during these post-bac years. I would've rolled my eyes at these words a few years ago, but post-college life has taught me that companionship and love with the right person are valuable and worth it in good balance. In her book "Lean In," Sheryl Sandburg said her partnership with her husband has been a key factor in her successful career and her ability to balance work and family life. If you want to be with the person in CA, then make it happen. Practically, my husband will be able to pay for living expenses while I am in school, and once I graduate we are going to throw my first year's salary at his college debt. Partnership! He doesn't limit my career opportunities; he only supports them. If your love is a true life partner, then I would only recommend holding onto him/her. If not, there are other potential romances in this world, and I wouldn't build your career steps off of this person's location. Best of luck!