No vehicle is perfect nor free of mechanical issues. The problem with forums is that more often times only people with bad experiences post their problems, whereas people who dont have any issues have no need to post anything online. So a quick google search or skim through forums may yeld a false impression of how reliable or unreliable a vehicle it. I just watched a mini series on youtube "Expedition Overland" and learned alot about Toyota's. But most of what I learned was not from the series, rather the comments people were posting for the video. Many of them were obviously Toyota lovers and one thing most of them seemed to imply was that Toyotas are much more reliable than Jeeps. Unrelated last year my supervisor received a letter in the mail from Jeep. It was to inform him of a potential fire hazard due to a weak spot underneath the truck that would potentially cause a fluid to leak onto the exhaust and catch fire. .... Jeeps have had their own issues just as Land Rover has had their but it seems like people try to hide that fact. People often tell me that Land Rovers are junk because "they are British" etc. For a long time Jeeps suffered from major chassis and body rot issues, weak suspension, the death wobble, weak diffs etc. Land Rovers prior to the 90's were pretty decent then BMW bought the company and things went sour. The main issue affecting Rovers from the 90's up to 2004 was the American made Buck V8 (renamed Rover V8) that was prone to blow head gaskets, cracks in the wall if overheated, engine ticking, missfires, slipped liners etc. The electronics were another issue. So many computers on board. For example if your brake pads get to thin or one of your wheel hubs starts to show signs of failure then the computer system will light up your dash cluster like a Christmas tree (3 amigos) and of course the only way to read and delete the codes is a ABS code reader/diagnostic tool. But the main issue with the 90's Rovers was neglect. For some reason these vehicles seem more sensitive to prolonged oil changed. They dont really like when you let the oil get to low. Some vehicles can keep on running for a long time with a quart of oil, but not the Rover v8. Seems alot of people felt that because they paid so much for the vehicle, they did not have to worry about changing the oil on time, thus the engines break down and LR gets bad rep.
That said the Discovery 3/LR3 came out with a couple new engines (no more Rover V8) no more issues with slipped liners or engine ticking or premature headgasket failure. The V6 version uses a Ford Explorer engine if Im not mistaken and the V8 uses wither BMW or Jaguar engine if Im correct. The 3 amigos was probably addressed as well. So it seems like the Discovery 3 is a much more reliable vehicle with a refreshed design.
Change the oil on time or sooner, check your air suspension every now and again, change diff fluids on time and you should be just fine. The advantage of owning a Discovery 3 vs a Discovery 4 is that the market for aftermarket replacement parts and off road parts is finally opening up and more support is becoming available. it just takes time. Rovers north, Atlantic British, Lucky 8 llc all specialize is selling aftermarket parts and mods for Rovers including the Disco 3 for more reasonable prices. Youtube has videos on how to replace the air struts and air compressor. Airnottt suspension now sells air suspension parts for the RR and Discovery 3 for considerably cheaper than genuine. Land Rovers are not much more expensive than any other vehicle. You go to the dealership with a Jeep and ask for service or a new part and you will pay with your limb, same with every dealership for every car make. The key to owning a newer Land Rover such as an Discovery 3 is aftermaket parts from companies who specialize in Rovers. The LR community is huge and there are plenty of businesses that cater to them. Just do your research, open up to DIY work, buy aftermarket parts and save tons of money. Simple. Just find one with a wealth of service records so you know it was well cared for. The only reason the Jeep has such a high value is demand, not practicality or reliability. LR has considerably less demand in the US and they are feign so they will cost more and lose their value quicker.
Good luck and thanks for checking out the LR section.