I have HSI Enhanced and have had it for 10 months at this location and for a number of years at my previous location. Last October I was connecting at 3360 / 832 kbps. After some months it went down to around 2800 / 832 kpbs. I wasn't crazy about speeds getting lower as time went on rather than the connection being improved, but it was pretty much free of disconnects and reliable so I was happy with it.
In the past month or so I had noise on my voice line which Verizon fixed, but my connection is now 1792 / 448 Kbps all the time, that is a drop I will not accept if this is the way it is going to be from now on. Also there is a lot of losing the connection, not to the DSL, that light stays on but the internet light goes off. I went through the usual channels online chat, telephone support to wherever that goes. I'm done with all that, that's good for people with trouble using their modem, etc. or can't connect it but not what I am looking for.
Finally they sent out a tech who was a nice enough person, what he did was call a central office and after them first claiming the lower speed was the right speed they put the connection back in the area of 3360/832. Then they said it will probably adjust itself to down around 2800 down, which it what I had before so I was OK with it. After several days with a number of disconnects (they don't last too long but very annoying) I am back to 1792 / 448.
I am using the same modem - Actiontec GT704WGB
I don't need a tech call here in the house again, nothing has changed in here since I moved in months ago. They can check the outside signal without me waiting around for them. They don't have to stand in here to call an office on their tablet.
I need to hear from Verizon personnel that can tell me LOCAL information about why my connection speed has tanked and why there are dropouts now. And most importantly, why it can't be the same as it was for all those months. As I said, I was happy with that - especially when it was 3360 / 832 kbps.