I have an ND Aquatics tank, though as I only got it in January I can't say what it will be like in a few years. But so far I'm impressed with the tank and the stand.
The only downside I can think of is that I live outside their standard delivery area and had to pay a delivery supplement.
I had an off the shelf 125 litre; the plastic bracer bar came away from the back and the glass was bowing. I didn't want to risk repairing it myself, and besides, it was a good opportunity to get a bigger tank. The off the shelf tanks the volume I wanted were all to deep, and when on the stand would have been to tall for me to reach in properly. This was the main incentive for getting custom built - the new tank is just 18 inches deep. The bonus for me was that the new tank is made of 10mm glass unlike the 6mm glass in the old tank. And I could choose an opitwhite front panel for a small extra price.
Edit to add that the cost was pretty much the same as most of the off the shelf tanks of the same volume.