I can't post a link but go to statesavings.ie and download brochure 2 and brochure 3.
If you invest your 50k in a savings cert, after 5.5 years it'll be worth 60,500
If you invest your 50k in the 10 year solidarity bond, after 10 years it'll be worth 73,650
If you encash early you may be much better off with the cert than the S bond - AFAIK much of the gain from the S bond is from a bonus at the very end whereas the cert gains interest more steadily and interest is calculated every 6 months. The brochures will explain this. Remember that there is no DIRT with the cert but there is with the S bond so you will see gross and net figures for the S bond.
If there is an increase in DIRT in coming budgets this may affect the returns from the S bond but won't affect the cert.