I've been with VPSSlim/Hostslim for about 3 months now. In the beginning, i.e. the first 2 weeks, all was well. Performance was great and so was uptime. But then the horror started. Nodes are extremely oversold and therefore very unstable. I/O is usually piss-poor and everything feels slower than a Celeron mining Bitcoins. I've been moved to another node because of this, and the same it was exactly the same story; The first 2 weeks were great, but after the box got crowded, it was sluggish again. VPSSlim/Hostslim is a one man show. There's nothing wrong with that, but Ralph, the owner, likes to solve problems using a game that's called 'Is it better now?' If you open up a ticket, complaining about the performance, he will update the ticket in 5-15 minutes asking 'Is it better now?'. Sometime it is, sometimes it isn't. What I can tell you is that it isn't better in the long run.
6 days ago I got this email: Lately you might have experienced some load/connectivity issues with your VPS. We have been working on this issue very hard and this should be resolved now. We are just sending you this message as status update.
2 days ago my VPS was down for 14 hour(s), 27 minute(s) and 18 second(s)) due to 'connectivity issues': "You may have noticed that you where not able to connect to your VPS. The problem was caused by a routing issue and we had to reboot your VM. Your IP should resolve again and you should be able to access the internet again through your VM."
Today my VPS went down again, which was quickly followed by an email of Ralph, informing me that 'Some clients have contacted us that they could not connect to their vps after 5PM GMT+1(Dutch time). This was caused because they are hosting a firewall and the right rules where not applied. To fix this issue they had to reboot their VPS so the new rules applied to the iptables.'.
I am sorry, but I'm just not buying this. I never heard of this before. I am not hosting a firewall, in fact I haven't logged into my VPSSlim box for 3 weeks because it's just so slow and unstable, and now my firewall is not properly configured? Nope. Also, isn't it a bit wierd all problems are fixed by rebooting? Routing issues, firewalls, a simple reboot fixes all...
Anyway, all in all HostSlim/VPSSlim tries, but that just isn't enough. Nodes are oversold and unstable, but on the other hand 'Support'/ Ticket responses are be fast and friendly (except for the last one I got, which was a bit rude). In the end that doesn't matter if the service quality does not improve. Therefore I would not recommend VPSSlim/HostSlim to anyone.