What would you say was the best example of a pre-Jihad IS XLE?
Well the Berserker is a surprisingly well-done one. Whole bunch of armor; makes the most of the XLE to get extra speed both to get its hatchet in range and to avoid fire; MASC for added effect; AMS and ECm for increased survivability to get 8it in close; Flamer for anti-infatry and firestarting. I can't give it the medal though, since it still uses a Hatchet. Awesome though they may be, they're a waste of space.
So my personal favorite use of the XLE prior to the Jihad, and this is just going off of memory, would be the Falconer. It's a 5/8/5 large heavy with both a Gauss Rifle
and ER PPC, and a salvo of MLs for in-close work. It moves fast, hits hard, and has enough survivability to take msot hits that are thrown at it. It probably comes closest to approximating a Clan mech of any of the early IS reactionary-designs.