I use my phone for tethering every now and again and also use a MiFi. Things to watch out for if you are thinking of this:
1) Make sure your provider allows tethering. Most do (maybe they all do nowadays because of competition), but it is worth checking. I have heard of "unlimited" packages for phone data which rather uselessly don't allow you to tether -- it sounds incredible but this is something that can be optionally provisioned on your phone by the provider.
2) You don't have to use your phone. Most providers also offer a "MiFi" dongle -- a tiny wireless hub the size of a credit card (but fatter) which takes a SIM card and frees up your phone and phone battery. They typically cost a few tens of euros but may be discounted or even free if you are going with a new provider for data. A MiFi also gives you the most up-to-date connection without upgrading your older phone, e.g. just in case your phone doesn't do 4G. It will also have a slightly better wireless range than your phone, though not as good as a full size router (which would also have Ethernet ports for connecting things like older wired printers).
2a) Just to note: if you get a MiFi with a provider contract it will be locked to that provider. You generally can't switch to another provider's SIM. You can buy your own 4G router which is not locked, but will be considerably more expensive (up to €150 or so) and probably not worth it. If you go with a provider, it is very important to check for a cooling off period. Many of them allow you to return it within 14 days if it is not working out for you, which brings us to:
3) Perhaps most importantly, if this is for your home check out the signal with
each provider you are considering. Each of them may operate off different masts and speeds may vary considerably. Especially if you are urban (which you probably are if you have Virgin Media), also check the signal at different times of day. Run a number of
speed tests.
4) Mobile broadband quality is variable. VoIP can work quite well over the right connection, but sometimes latency increases and it gets patchy. A mobile broadband package will not be suitable for loads of video or video calling as the data volumes are just too high for most packages (unless you can find a genuinely unlimited one).
5) If you are using an older desktop machine you may need a wifi dongle to connect wirelessly (but you probably already have this figured out from your VM setup).
I'm not
au fait with packages I'm afraid. I use a 1GB package from 48months for extremely occasional phone tethering, and a Vodafone PAYG package with a MiFi which is expensive but can be bought in small increments which suits me. If I was looking for a home broadband replacement, just glancing around I see that
Eir has a 25GB package for €20 with a free 4G MiFi on a 6-month billpay contract. Something to look out for with PAYG packages is when unused data expires. In some cases it is quite short, I came across one recently where your data lasted 180 days but I'm afraid I can't remember which provider. Will get back to you if I can think of it.
EDIT: found it, it was Meteor (
see this boards thread) but Meteor have been subsumed into Eir and I don't think the packages exist anymore.
EDIT2: No, I tell a lie! The
same PAYG package still exists under Eir -- €30 for 50GB with 180 day expiry. This is probably one of the better deals around especially for light users. You can even take it roaming under the mandatory new EU rules. As it's PAYG you will have to buy a MiFi. I see they offer a (presumably unlocked) 4G router for €149 (as I guessed) and a 4G MiFi for €79 (ouch, pricey! -- if buying this, check it is unlocked, it should be at that price). There's a USB dongle version for €29 but this won't allow you to connect multiple devices wirelessly. You might find a cheaper https://www.amazon.co.uk/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=unlocked+4g+mifi (unlocked 4G MiFi on Amazon) but then you will not get any help from Eir if things go wrong.
Maybe the sensible option is: take a six month contract with Eir at 25GB/month for €20 to get the free MiFi. Effectively the six months costs you €40 compared to having to buy your own MiFi. Then go PAYG thereafter. (Check if you own the MiFi and can have it unlocked after the 6 months).
But don't forget rule number one! -- test the performance you are going to get before you commit to anything. And check you can return the MiFi as well as the SIM. The last thing you want is to be instantly tearing your hair out over an unsuitable package.
It is a far more reasonable £66 on Amazon or about what I paid for it here and, like the one sold in Maplin, is unlocked for any network worldwide. There is a slightly more advance one (M7350) also available but was much dearer at the time of purchase so I didn't bother with it.