I doubt your statement. 5-6 streams at 10MBit/s are 50-60MBits/s - 802.11n (which has only been around since 2009 officially), is supposedly good for a thoughput of net 40MBit/s under good circumstances. Repeaters do not enlarge the bandwidth, only the covered area.
Good that your clients did not see any problems.
I will not trust wifi for my media consumption need, except maybe audio.
Its has nothing to do with 'trust' - its simply a matter of engineering, physics and spending the time needed to set Wifi LAN's up properly.
Our clients don't see throughput problems because we spend time installing and optimising their wifi - the results are worth the extra effort/cost (in most cases). There are always situations where a 'thrown' together wifi LAN will do the job - and of course the industry likes to portray wifi LAN's as something anyone can setup in 2 minutes with no technical effort! That's simply marketing crap. But if you want to extract the maximum from wifi then you need to spend the time/effort to get it.
In real world use with a properly configured Wifi LAN (using good quality hardware), and good coverage throughout the property (that's where the wifi repeaters are important and better signal quality translates into better throughput locally from that repeater - not for enlarging bandwidth) 802.11n can deliver 70Mbts+ and with 802.11ac we have networks delivering 90Mbts+. You need to use good quality Wifi AP's (a $45 USD unit will not have the throughput because its SOC and other components simply will never deliver it - a function of cost) and they need to be configured properly - and importantly the resultant LAN needs to be tested, and adjusted, if you want the maximum throughput.
See here; http://www.speedguide.net/faq/what-is-the-actual-real-life-speed-of-wireless-374
We see Wifi LAN's delivering broadly the throughputs mentioned in this article in real world installations - i've been personally involved with 4x such installations so far this year. They are all delivering reliable service at the throughputs mentioned above.
All the best