Rogue M-150 upgrade to M-180 Questions

So, if you have either done this upgrade, or heard a set before and after, what did you notice? I am wondering if the upgrade is a good allotment of funds (plan B would be upgrading my digital source, currently a Modwright Platinum 9100 Sony) Speakers are Tyler Acoustics Decade D1's, relatively easy to drive.

Things I like about the M150's (tubes are Svetlana 6550's, RCA Clear Tops, and Telefunkens) are holographic imaging, huge soundstage, deep bass. Things that could be improved on: clarity, tighter bass, as it can be a little boomy at times, transformer hum is noticeable.

Do you think the upgrade would make the amp improve in those areas? The increase in overall power would be nice, but I am running it in triode, as my speakers don't require a ton of juice, and UL mode just flattens out the imaging a bit, with no offsetting benefit.

On a side note, has anyone heard the upper-end Rogue preamps? I see one for sale on here right now.
Have you talked to Mark at Rogue?
yes, I have. I was just looking for a bit more info from others who have been in my shoes.
Out of curiosity what did he say?
Mostly along the lines of "it should sound better, more open, better woofer control". I am leaning toward getting it done, but they sound so nice at the moment....
I upgraded my 150 to 180 about 6 months ago and continued to use Golden Lion KT-88 output tubes. As I understand it you do not get the extra 30 watts of power unless you go to the KT-90 tubes. I have enjoyed the upgrade - dynamics improved and soundstage seems bigger and more open. Is it worth the cost - I think so and so does the reviewer at Stereophile (for what it is worth I think they put the 180 in Class A and it was in the running for amp of the year in the most recent addition)but as always YMMV. Also have you tried KT-88 output tubes, I have not used my 6550 tubes in awhile but I do remember the bass becoming tighter and more natural with the KT-88. Good Luck.
I have compared [at a friends house] 150s vrs 180s side by side, and even swapping tubes from one amp to another to keep variables the same. the 150s are warmer and rounder in and old school tubey way, the 180s have more extension from top to bottom with a wider deeper soundstage, and with string instruments it was like taking a blanket off the speakers, way more lifelike attack and sparkle, making the 150s sound rolled off and dull by comparison. this was with revel gems for speakers and bel canto dac 3 front end. I would say for most people the 180s are a great upgrade.
How much is this upgrade worth?I got the 150's at home and being happy overall with them so far.
if your happy, then stay happy!