I have enjoyed using the Karl Hammond mouthpieces. I use an 11L on euphonium. It has an interesting cup design that starts as a bowl/barrel and then funnels into the throat, that helps with air direction and creates a clear "HD" sound, as he like to advertise. The 11L is a little shallower than the Wick 4AL, and the rim diameter is just a little smaller, but bigger than the 5G or 51D. His 11XL is very deep, like the 51D. It is actually comparable to the 52D
If you liked the 5G, you can try the Hammond 12L, or 12XL for a deeper cup.
I played on a 51D in high school, 52D through a few years in college, then Dan Perantoni suggested I try the SM4 and I loved it, and played on that for almost 20 years until I switched to the Hammond in January. Why? I was looking for a more focused responsive sound. The Wick tends to have a "Woofy" sound as I have heard it described.
Just a thought. Good Luck.
Raul Escobar
1985 Willson 2900BS, Hammond 11L
1974 King 4BF Silver Sonorous, Hammond 12ML
1972 King Duo Gravis, Hammond 20BLL