.Net Web Application Performance

I have a .net web application utilizing bootstraps. At our office we have very high end machines with great wireless network cards. However people on slower pc's and cheaper network cards are increadably slower, even when they are on a great internet connection. For instance I am writing this on my home machine which is an HP i7-3630QM CPU 2.4GHz, 8gb ram, RalinkRT5390R 802.11 WiFi Card on a 30mbps internet connection. Now I realize HP is crap and the network card is crap. But the problem is this is the type of system most people buy. Long story short the system is at least twice as slow on these machines, most of the time 4 times slower elements just never load at all and my users have to refresh the page a few times to get things to work.

We also have New Relic to measure server speed and it never maxed out on the Microsoft Azure platform. In fact our slowest page is only about a 3.5 second loading time.

We are working on the system to try to implement more ajax, dom cacheing and what not. But nothing so far seems to make a big impact.

So I guess my questions are why would things be so dramatically slower and not work at all some of the time on these machines with crap network cards? Is there any software out there that could help us track down speed issues on the client side? Also is there any services out there anyone could recommend that specializes in .net code optimization for speed improvement?

Thank you in advance.

via Chebli Mohamed