Working from home today, so thought I'd take some quick and dirty photos of my Leuku and Terrasaur. Doing this on the fly, so apologies in advance if some of it doesn't make much sense
Couple of shots: both are 5/32" 01, but as you can see the Terra is TT and the Leuku is SFT.
For me, they are two different models (well duh~ but please see below). Just some general comments for each model:
1. Leuku: Now I got this knife because like you, I love my recluse. I liked my recluse from the start because of its capability despite its relatively small form factor. I've found the contoured handle to be very comfortable for my larger hands (I wear between L and XL on most gloves), and I also found the primary convex grind to be quite shallow, making it an excellent cutter. Now they didn't necessarily translate directly into (my) Leuku. The convex'ing is a lot more pronounced on my version of Leuku (so steeper angle leading to the cutting edge), and the handle is also less contoured. Furthermore, the Recluse feels ever so slightly handle heavy vs. Leuku being ever so slightly blade forward in balance. These elements made it a completely different knife for me even though on the surface, they look like the larger (or smaller) versions of each other. Not sure whether you can tell, but I actually thinned out a bit of the primary grind on my Leuku (with my water stones) to make it a slightly better slicer. In all, its more robust construction, longer blade handle, and less contoured (relatively speaking) handle makes it a great small(ish) camp knife for me.
2. Terrasaur: Now I just got this couple of months ago, and will admit didn't get a chance to use it thoroughly enough to provide any solid comment. But relative to Leuku, the handles are more contoured, balance feels very centered (very nimble overall), shorter blade, and actually slightly longer handle. It's a drop point, but still has plenty of belly. And the primary bevel is shallower than Leuku (but possibly a stronger tip than Leuku). Just based on my personal experience, I know that, in general, I'll pick the Terrasaur over Leuku 9 out of 10 when it comes to practicing my bushcraft skills (unless I'm doing something heavier like shelter building). But I've also re-profiled the heck out of my Leuku to my personal preference, so both are excellent (for my purposes, mostly bushcraft/camping/backpacking/etc) in my opinion.
As you know, some of these elements will vary from knife to knife for a given model, so my comments are solely based on the specific Leuku and Terrasaur that I have.
Hope this was at least slightly useful.
Josh
Addition: Another view of the Leuku re-profiling from an older post