I think
@I Heart Noise is frustrated because HD grabbed a name that probably has no end user. It may have a bit of traffic stemming from past development but will it ever sell ? Doubtful.
Had he dropped a name like ihn.com, he would understand that HD or another entity would have caught the name because it is valuable. And they would ask a lot of money for it. But a random 5L.com ?
Sorry
@I Heart Noise, it's nothing personal here, just business.
I am not a fan of HD personally but what they are doing is more or less what we are doing on a much smaller scale. I have bought hundreds of expired domains and it is inevitable that among those a few may have dropped accidentally. But the majority are clearly abandoned - I have seldom heard from the previous owner.
Many years ago, I dropped a few valuable names, because I didn't realize the value back then (and the value of traffic). I have learned my lesson.
Obviously you've been asleep at the wheel. Domains don't drop in one day. It means you probably stopped working on your site for a while, otherwise you would have noticed it was no longer working. Now that the domain dropped, I would guess the ranking will suffer anyway.
I think the the best course of action would be draw the lessons from this unfortunate experience and maybe consider rebranding yourself. In my opinion you are going to switch from a poor name to a worse name. I understand you rely more on backlinks than word of mouth but the name is not very memorable.
Also, iheartnoise.com is in use, so branding yourself as 'I Heart Noise' is not a good idea. I don't know which of the two came first but I would want a more distinctive identity.