You've definitely got to try a few - if they're going to do some work on the gearbox, it won't sell for a bit presumably if it turns out to be the one you want. Mind you knowing there is an issue, might be worth giving it a miss anyway!
My '99 (L Series) gearbox I'd describe as OK - not sporty crisp or sloppy - just OK. Although reverse is a bit vague which I think is pretty common.
There's been a popular thread on here recently about Freelander reliability and the consensus I believe was very positive. There are some annoying things like drop links that pop up often and a lot of the issues here I think are with 'cheap' replacement parts that aren't up to the job an fail very quickly. Its worth spending a few extra quid on these types of bits if they need replacing. The BIG thing is the transmission - the VCU - which I'm sure you're fully aware of. Its absolutely critical to keep on top of tyres and tyre pressures and don't get lazy with them, or it'll bite your bum - or at least your bank account. I don't know if the 'cracked chassis' was fixed in later models, but that's a problem the Freelanders are/were prone to - have a search for it on here if you've not heard of it.
When you're looking at Freelanders - make sure you look in the cubby box in the boot floor - its a good sign of whether the car is water tight - its not called the goldfish bowl or fishtank for no reason. Also the passenger footwell carpet - that can get wet for a number of not so nice reasons.
I'd had Discos (TDI & V8) for over 10 years before the Freelander and initially I found it a bit boring, but I love it now, great car. I've piled on the Ks touring NZ without skipping a beat (well it did once!) and with great economy. When I've stuck the boat on the back and laden it with a few 100 Kgs of camping gear its got the family comfortably over mountains and twisty backcountry roads. It takes me fishing, skiing or down the shop equally well. Top car.
The only time it has let me down was when I got lazy checking the tyres, distracted by having friends visit and just wanted to go out touring - and an under inflated tyre caused the VCU to blow the IRD. It is a shame such a simple thing can cause such major problems, but even given that, its still a top car.