I have been with Virgin Media since 2006 (back when they were NTL) and have always been on the fastest package they have offered alongside the highest level of service on TV and Telephone.

Until around 2015, the service Virgin Media had provided to me had been exceptional and I never had any complaints. Often referring them to friends and family. The e-mail service was great (provided at that time by Google) and as it was the majority of our families first e-mail address (and one we had used for many services over the years), this was important. In addition to this, the speeds had always been way ahead of the competition and were incredibly fast and untiil 2010 were MILES ahead of the competition (and still are today, arguably).
The company had provided me with a cable modem (upgraded over time) and we used our own router which worked flawlessly and I always recieved my full speeds over both. I was dreading having to change my modem so I did not, opting instead to keep my current setup (I had heard horrors about the Super Hub)

The first hurdle came when Virgin Media were forced to migrate their e-mail platform. Instead of researching a good way of doing this - they ended up going with OpenXchange (notorious for being quite bad!) and as such this caused major issues for my whole family who had relied on this e-mail service for years. Now, we're lucky if we can log in to the webmail client at all, it often just not loading my e-mails. I am lucky and have used Thunderbird since the mid 2000s and it did not effect me personally. However, this was the start of the downfall.

However, eventually I was forced to migrate to the Super Hub and I did so (not so willingly) - at first the SuperHub 2ac was perfect - in Modem Mode and out of it. There was very little issues and the service level was good as always. I had few complaints (minus the stagnation in speed improvement) but other than that I was pleased. The default router was atrocious for signal, so I returned to my trusty flashed one and started to notice that in Modem Mode there seemed to be a deliberate speed reduction. I had turned Modem Mode off and my speed returned to full (while still using the same, custom router) so left it as it was.

I returned the device to the default mode eventually (Virgin refused to support it in Modem Mode!!!) which worked fine for me after some firmware updates and I left it as such.

When I was upgraded to a SuperHub 3 (when we recieved our V6 box due to Sky Sports changes) the connectivity took a nose dive (stupid latency & lowered speeds and constant disconnection). I was used to the simplicity of having it in one box but decided to return to modem mode to have the same faults. I had the router replaced several times and while the issues are now less prevalent they still occur more frequently than they ever did and the latency is much worse than it has been previously.

In the end, Virgin have shown a disregard for me recently as a customer as ever since Liberty Global took over the service level has downgraded over time. Fortunately, Vodafone are looking to expand FTTH to my area - so I may be able to replace my broadband service soon.