OUR SAMPLES - One of the great things that Family Tree DNA (FTDNA) does is to store our samples for "25 years". I put "25 years" in quotes because no one seems to know how long the sample will actually be viable - but the belief is that it will be "at least" 25 years. So - if your uncle Bill is the last remaining male in your surname family, or if Aunt Susie is the last remaining daughter or daughter's daughter of Dad's paternal grandmother, it's time to get them tested - so that you'll have that precious family dna as time goes on and our older generation passes on to their Reward.
One of my regrets is that I tested my Grandfather's youngest brother through a company that didn't retain samples. He's gone - and so is the sample. I wanted to upgrade his test - but will never be to do so.
UPGRADING - A number of folks think they will need to provide a new sample if they order an upgrade. Nope - not if you have already tested at FTDNA. They retain your sample - unless you specifically instruct them to discard it. (which I would never do!) And, other folks ask - how many upgrades can I get with my retained sample before it's all used up? FTDNA once told me - "we can run as many upgrade tests as you can afford to buy!" There were teasing - in a way - but the reality is that FTDNA can continue to generate a sample for your latest upgrade as many times as you order.
SO - SHOULD YOU UPGRADE? The answer is always - "it depends" - and the question becomes "what are you trying to accomplish?"
12 MARKERS - If you have a 12 marker yDNA test - it is almost always - "Yes - you should upgrade" - as the 12 markler test is only good for 3 things:
1. Getting your sample retained for 25 years
2. Proving you DON'T share a recent common ancestor with someone else who has been tested
3. Confirming a solid paper trail to a specific someone - where the match on this few markers is sufficient to satisfy that nagging doubt. (and sometimes - you'll still need to upgrade - if you are one of those folks with a couple of mutations in the first 12 markers)
25 to 67 MARKERS - Generally, I consider 25 markers to be the bare minimum for genealogical purposes. Usually, you'll want 37 or 67 markers - but you'll need someone to compare to at that level - so your choice will be affected by how many markers have been tested by the men you match - or think you may match. You'll want to test as many markers as they have tested - so you can get a full comparison. And - if you are a "leader" - you may want to set the standard at 67 markers for the others who match you to follow.
For my own projects and my own family members - I consider 67 markers to be the "Standard" - as I want as much information about matching and branching within the Lineage" (Genetic Family) as I can get
EVEN MORE MARKERS - You can actually test over 67 markers at FTDNA - with a total that is in the 120s. In order to do so, you'll need to select "Go to Advanced Orders" instead of "Go to Standard Orders" after you click on "Order Tests and Upgrades". The additional Markers are way down the page - in Y-STR DNA-FP Panels 5,6,7,8 & 9. You will also find some markers in Panels 1,2,3&4 that FTDNA doesn't test in their first 67. My suggestion is that you order these "advanced" markers only in conjunction with others whom you already match - possibly in a study being done by your surname project.
SNP TESTING - this is the formal test to determine (or confirm) your haplotype. FTDNA has promised each of us that we'll either get a haplogroup estimate from them - or they will do a SNP test at their cost - to determine our haplogroup. Lately, SNP testing has advanced to the point where "DEEP CLADES" are being defined by testing a number of SNPS. This allows you to know with much more specificity which branch of your haplogroup is your own branch. (For example, my own Deep Clade testing is to the maximum available level - and I am classified as a R1b1b2a1b7c* (or R-L2 - which is the last SNP in my confirmed haplogroup) by FTDNA - who uses the YCC Tree.)
You won't find the order link for your SNP or Deep Clade test in your "Order Tests and Upgrades" You'll find it in your yDNA "Haplotree". If you haven't looked at this page in your FTDNA Personal Page - you should - as it interesting to see where you are on the tree.
DEEP CLADES - Only one member of a Lineage really needs to be be Deep Clade tested - as all of the other members of the Lineage will (should) get exactly the same result. At some stage - possibly far in the future - we may get so deep into our Clades that we'll want to test members who are on different branches to learn their different Deep Clades - but we are still many SNP levels away from that level of detail - so one member of a Lineage is enough for the foreseeable future. (SNPs are being discovered all of the time - and our level of detailed knowledge in Deep Clades is advancing rapidly)
Note - more information is never a problem - so if someone in your Lineage is already Deep Clade tested - you can still do it. It's reassuring to see more than one man with the same Deep Clade in a Lineage.
More on other forms of upgrades (such as mtDNA, autosomal, X-Chromosome) later - in other postings.