What the Crossbar Buys You
Put both hands on the bar and the shovel stops being a one-arm tool. You can press straight down with your weight centered over the blade, twist the whole shaft to saw the edge through roots, and pry back with both arms instead of one wrist. The bar also gives your boot a square platform to drive against, so in hard ground you dig with your legs instead of your shoulders. None of that shows in a product photo, but it is the entire reason the style exists.
Ground That Asks for a T-Handle
Deep relic targets are the classic case. A buckle or a large copper at a foot or more means a real hole, and cutting one through compacted field dirt is leg work, not wrist work. Root-laced woods soil is the other one: the twist-and-saw motion the crossbar allows is the cleanest way through a root mat without hacking at it. Clay rewards the two-handed pry when a plug refuses to release. If your usual hunt is shallow park clad, the crossbar is more handle than the job needs; on field and forest digs it earns its keep by the second hole.
T, D, or Straight?
A D-handle closes a loop around one hand, which suits thick gloves and one-handed lifting but gives up the wide two-hand bar. A standard straight handle is lighter and packs flatter, and it is the better all-rounder when deep digs are occasional rather than the point of the trip. Compare the whole wall in all shovels, diggers and picks, and if the kit is still coming together, start with metal detectors and add a pinpointer for the bottom of the hole.