When I started playing it was the Arbitrator that I wanted to fly, I loved the look of the ship and the drone bay on the ship appealed to me, after all I could picture drones flying in/out of there.
Next it was the Orca, I can remember buying an Orca for 800m ISK in 2010 but having to leave it for two weeks because I had no characters who could fly it. The ship was a beautiful sight and really helped me when I started my mining empire and continues to serve me now as a short trip bulk hauler or a general support vessel.
Then in 2012 I was in need of a capital sized support vessel for my mining operations (now in Providence). There was only one choice and that was the Rorqual, instead of buying off the market I actually mined and produced ship myself in a low sec location and once finished I fit her and jumped to her new null sec home.
The Rorqual was unique, at the time, in that she could compress ore and ice (using the Industrial Core) to make it smaller and thus easier to transport AND she transformed into a structure like ship. Fit out with Cargo rigs and cargo expanders you could fit 137,000m3 into the cargo hold, 50,000m3 into the Fleet Hanger and a truly massive 250,000m3 into the Ore/Ice hold.
The Rorqual could also fit the Clone Vat bay, a Titan is the only other ship that can fit this, and it allows pilots to create a clone in the Rorqual that can then be "jumped to" at any time, but only once. the clone would be removed from the Rorqual and put in space but you could not redock with the Rorqual and then use it again later.
The idea is solid, imagine being able to clone jump to a Rorqual, participate in a large scale mining operation and then clone jump back. No need to have clones near to the Rorqual, you just jump to it and then grab a ship from the massive Ship Maintenance Hanger and start mining.
Alas it never worked like this, the Rorqual was unfortunately relegated to being a off grid booster and Ore/Ice compression service. Rarely did they leave the safety of a POS and rarely were they fit to survive in space, let alone under attack. I do remember, during the invasion of KBP7-G by PL in ~2011 that a Rorqual was used by PL to setup a staging tower, supported by their sub-capital fleet.
Aside from that I've never seen a Rorqual outside of a POS that hasn't been picking up Ore/Ice or is moving back/forth to station. There have been "Battle Rorqual" fits and I recall there is a player who excels at using one, but it's very rare to see a Rorqual outside of a POS.
Since the introduction of the shorter development cycles for releases the Rorqual has found itself in limbo. Ore/Ice Compression has been made available to all via Station Services so you no longer need to do this, and consume Heavy Water, in the Rorqual. Clone Vat usage has been viable but the recent change to Jump Clones nerfs this as well now.
The Rorqual really is a ship without purpose, sure it can still be used for mining and the bonus you get for activating the Industrial Core when boosting is worth using the ship but having this as the ONLY benefit really puts a question to the viability to the Rorqual.
CCP did say, many months ago, in a post that the Rorqual was going to be "fixed" but they could not do anything until other changes in game and the "back-end" were complete. I can't remember where I read that, but I'm pretty sure it was on the official forums by CCP Fozzie... but I could be wrong about that but I know what the message said just not where I read it or who posted it.
Citadels are coming, other changes are happening but still word on the fate of the Rorqual is non-existent.
Come of CCP, please give us an update on the fate of the Rorqual.