Though we used to use Siteground for a shared hosting site that stopped around 5 years ago so I would take more notice of someone with more up to date experience. Their Data Centre used to be in the Netherlands (Nederland) though I believe they opened one in the USA later.
We found their customer Support quick, friendly but lack lustre and did not often get to the bottom of issues pushing it back onto their customers. I have a Network and Server background so frequently had an idea what was happening and trying to get logs from them was almost impossible even though they would often indicate what was happening. The problem probably was dealing with first line support who were reluctant to pass onto more knowledgeable staff but once you got there it was normally quickly resolved. Their servers were reasonably fast and only had a little downtime. They had a DDoS attack at one time and we were off-line for many hours but they did move all the sites not the subject of the attack but on the same host to individual IPs so that they could be brought back on-line, putting them back once the attack had been thwarted. Most of the email was handled as far as routing etc by another and that organisations routing used some routes that were blacked mainly due to spam and that affected a lot of our mail. First time round when we mentioned this SG denied any reason why this was happening but when I tracked the mail and routes and researched I found the reason that they admitted they knew about it. Our contract finished several months later when it still had not been resolved. SG work closely with the Joomla and Wordpress communities and have developed a lot of extensions, templates, etc to assist. They are also involved in website security to the benefit of us all. I still use their Hackguard extension. Hopefully SG have sorted some of the negative experiences we had and five years is a long time in IT and web hosting.
These days we use a UK based hosting company called Rochen that have data centres in the UK and elsewhere. I cannot speak highly enough of this company and have used them for over two years. Originally I came across them in research and they use Litespeed as the web server and CloudLinux and compared with the other hosts that I have experienced they are really fast. Their prices are competitive throughout the life of your contracts so you don't get initially heavily discounted and then a big hike when you renew it stays the same. Originally this site was contracted for two years but that was renewed several months back for a further three. Don't think that the site has ever been down, except for maintenance, though it did slow down once but that was due to a bot trawling their servers doing a Google that they were eventually able to stop. Upon discovery of the slowdown they notified all customers of the issue and again when resolved. Their customer support is also good and in depth though we have little experience as we don't need to use it often and that is a good sign.
Incidentally on a personal level I use Arvixe in the USA for development and testing sites. Originally Arvixe was privately owned and I thouhgt highly of it but became part of EIG about two to three years ago and that was their downfall. The transfer of ownership and transfer of servers location amounted to many sites, including mine, being off-line for weeks going into over a month. In some cases the site went back on-line after several weeks and then went down again. Arvixe staffers originally contributed the the Arvixe community (forum) that was beneficial to all but that was stopped and there is no community any more since the EIG acquistion. Though they are not expensive, especially if you get a discount voucher/code of some form, and their servers are fast, I could not reccommend them for a production site unless a small club, etc. where the cost savings are more important than having 100% up-time. Having said that though only using in a small way I have not had any issues with down time since that earlier mentioned period. Their Customer Support arrangement appears to be odd to me, but luckily I don't often need it.
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