Whether you transfer it to a PRSA or a Buy Out Bond, you can still later transfer it into a future employer's Occupational Pension Scheme, if that's what you wanted to do. But there would need to be a valid reason for you to do so. If you are not a director of the future employer and you transfer your pension fund in, you lose the extra options at retirement you currently enjoy (i.e. Approved Retirement Funds).
Of Buy Out Bond and PRSA, the Buy Out Bond can be set up with lower charges. It's possible to set up a Buy Out Bond with no entry charges and annual management charges from 0.65%. PRSA annual management charges are generally 1%.