I have done some towing with my 90. I've done a couple of 88" series land rovers 350kms and 750kms at a time on a car trailer (800kgs empty). the 750kms trip had a bunch of spares + a spare engine and 3 people in the car. the 350km trip with a similar vehicle on the trailer + spares + an 88" roof strapped to the roof bars on my 90! Also did a 109 ute on the car trailer about 1hr down the road. Also done a bunch of towing of box trailers and camper style trailers over various roads - dirt, dry bitumen, wet bitumen, low range etc.....
The 90 tows great! Plenty of power to tow (2.5+tons) at 100km/hr (I've even done 110km/hr on good stretches) hills you have to sometimes to reach for 5th but no real issue - it's just a gear change. You want to be careful with loading, too much tow ball weight will be unwise - front end gets a bit iffy.
Dirt roads and wet bitumen I've mainly towed my home made slide on camper - 1.4ish tons. Handling is pretty good but just be careful on corners obviously - rear starts to feel loose, although I've never pushed to see where the real limit is.
Reversing is pretty good although I'm still getting used to it... the short wheel base tricks me sometimes...
The 90 is small on the inside - go look at one! 1200mm load bed less rear seats if you want to seat 4! So I guess it depends on what you use it for day to day.
Overall if I was purchasing a vehicle to tow all day everyday I would pick a 110 (no wait! make that a 130! not that i've driven one, but highway work towing I bet they are the ducks guts), the longer wheelbase is superior IMO. BUT the 90 is great around town - nice and small. I know the gear ratios are the same as the 110 but 1st is really good - nice and low, your not smashing your clutch trying to get rolling (had a pk ranger ute previously - I think 1st was WAY too tall for towing). The 90 is also great fun just cruising around and general 4x4ing.....

