Hi Joël
I think the logic behind the greater and smaller than is alphabet based.
I am going to use greater than as an example, for smaller than it is the reverse.
It gets really interesting if you filter wider than that:
If you would enter your name for example and say greater than:
For your case (strings with numbers), I'm afraid this will have different behaviour compared to integers or longs, as it sees your number as a string.
If I have a result set of the following: {1, 679, 699}, and would enter 679555 as a search criterium, only the 699 would appear as a result.
I hope this can serve as an answer to your question.
Good luck!