Not a problem. My setup is as follows: -
I live about 600m (in terms of line length from cabinet) and previous to owning any FTTC, I had Sky ADSL2+ that yielded about 15Mbit. (IIRC, up to 16Mbit was all Sky did at the time when we migrated to them from BT Broadband. I would never, ever, choose to go with BT - my wife (we weren't married then) had previously had up to 8Mb ADSL Max with BT, and despite the sync rate being 8Mb, it only ever went at 3Mb and BT were having none of my protestations. That's going back nearly 10 years now!)
We had a Huawei cabinet installed early on in 2012, and it was around the exact same time that Sky launched their FTTC product. It was 40/2 to begin with, and I upgraded immediately to Sky Fibre Pro in the June of that year.
It started out at about 72Mb but crosstalk etc over the years brought it down to 62Mb.
Fast forward to today, I decided that it was about time I moved to an ISP such as AAISP as I was lured by the amount of control I had over the line, and I firmly agree with their stance on providing "unfiltered" internet. I actually initially wanted to move to AAISP back in January, but because I am with Sky, and that is full on LLU, I'd have to get the line moved back to BT before I could get an AAISP service on it. I was not too enamored by that idea, since I work in IT and I require having some form of decent fixed broadband. I could have gotten away with tethering, but, decided against not dealing with any of the hassle, and simply having a second line put in.
I would then decided to chop one, or the other depending on how AAISP worked out. So at the moment, I have both lines up and running very well, and my physical setup is as follows: -
I have a single HG612 for each line, and the WAN ports are trunked to VLAN 100 and 101. I have a small switch under the TV in the living room where both the modems are connected to. I then have a cable that runs outside, up to the spare bedroom, where it is then in my core switch and my small rack.
I have an ESX Server that than has VLANs 100 and 101 trunked down to it, and a virtualised pfSense instance dealing with the routing. This then allows me to do outbound load balancing, and it seems even for mundane web browsing, it works perfectly and even mobile phones can see 99-102Mb on speed tests. I suppose to see the best benefit, I could actually migrate my primary line to AAISP too and then bond them..
As it is now, when I am downloading, I usually use SFTP that allows me to make many connections, thus this gets the benefit of the two lines too, I am getting about 105Mbps just now - but it should bump up a few Mb when my new line completes training.
Ultimately, I really don't *need* both lines. One @ 62Mbps would be fine. However, I have worked in IT since 2004 and grown up with it since I was very small and it is my passion, so having the ability to have two lines and do interesting things is well worth it for me. It is nice knowing that I can suffer an outage with Sky and keep running on AAISP. I could easily add tethered mobiles as a backup to pfSense by using a wireless -> Ethernet bridge. This could be used in the event of both lines going down (That's rare). My wife has the same mobile carrier as me so could tether off her phone too. I get about 85GB of mobile data between my 2 phone contracts (one for work) and hers. I think I've got it covered?
I am a Networking Engineer by trade, and am a CCIE, so networking is a joy.