No drawbacks at all. In fact, for people new to testing it is by far the smartest choice. The XL leaves lots of extra reagents to learn with. It is literally counting drops and is *that* simple. No matter how scary the big kit seems. In said kit is a big lamentated card with each test detailed. If you glance at the whole page it seems insane. Look at any specific test and it is CAKE.
Fill tube to 10ml,
add scoop of powder,
count drops of 0871 reagent to turn newly pink vial to clear,
each drop equals 1/2 PPM FC
BOOM thats it. (And every test is similarly easy).
But at first you'll be nervous and mess up a but. Then once you get it you will test WAY more often than normal as you learn your pools character and habits. You won't trust yourself so you'll run tests several times. Once that subsides the chemicals usually expire at 2 years before most people run out.
So the XL for you is a great choice. Also get the speedster. Having to aggressively stir the test vial while adding drops with the other hand and counting can be done, but why. Certainly not for $30.