I'll repeat a post I made at 23andme on comparing success rates at both:
Colonial American ancestry: Jamestown, Boston, Cambridge, Hartford, New Haven Colony, New Amsterdam, New Sweden, New Jersey, Pennsylvania. Then spread out to North Carolina, South Carolina, both pre-Rev War; then Tennessee and Kentucky, post-Rev War.
- at 23andme I have 1050 RF matches and have confirmed 7 of those.
- at FTDNA I have 175 FF matches and have confirmed 10 of those.
- Two of my confirmed matches have tested both 23andme RF and FTDNA FF.
- I have 20 separate X Chromosome matches in RF and AF. That counts repeated people only once.
- I have no immediate matches at FTDNA. I have 54 close matches and 121 speculative matches. My closest confirmed matches are two 4th cousins.
- I have two known 1st cousins at 23andme and two unresponsive 2nd cousins. My closest confirmed match at 23andme is with a 3rd cousin once removed and her daughter.
If you haven't done any tests I recommend starting at 23andme and then, when FTDNA opens the program, transferring your results to FTDNA. That way you get genealogical matches from both companies, you get mtDNA haplogroup and if a male, Y DNA haplogroup, and X chromosome matches at 23andme plus health info.
At FTDNA you get genealogy matches and when they get it ready, X chromosome matches. You have to pay separately for the Y DNA haplotype and haplogroup and the same for mtDNA. So from a cost perspective it is lower cost to start at 23andme and transfer to FTDNA UNLESS you also want detailed Y DNA /mtDNA readings.