I have a '06 2544 with the dozer blade. I've "plowed" over honeysuckle, move small dead tree trunks (about 6" diameter and 10-20' long, and used it to spread and level gravel and dirt. The blade is very heavy duty, which is why it costs more than 2X the snow blade for the 1000's and 1500's.
I never experienced any hood problems. But my dealer did replace the entire hood when I took it in for it's first scheduled maintenance last December. He said he did it because Cub had issued a TSB or recall on the hood latch. I wasn't having the problem but he figured that the tractor was in the shop, I wasn't in a rush to get it back, and Cub was paying the bill, so why not?
I've only talked to two people personally that own 2500's, and they too never experienced a hood issue. But they bought from my dealer as well, so it's possible that the dealer dealt with the problem before delivering the tractors.
As for the people here that have had the problem, there were some variations on what actually went wrong:
The first issue was a latch failure. This occured slowly and would cause the hood's "closed" position to creep higher and higher. This would eventually lead to the exhaust being partially blocked, and thus melting that portion of the hood. This was resolved by Cub back in late summer/early fall of '06 with a redesigned latch, and a TSB was issued.
The second issue was heat under the hood. Someone took the time to measure temps at various locations and compare them to what Kohler recommends for their engines. His reading were higher than what Kohler told him they should be. I also took temps and got results that were a fair bit lower than his. Best guess is that this excess heat issue was really only a problem on the 2550's and 2554's, probably because the decks were much larger and put much more of a load on the engine. But in any case, Cub has put out at least 2 updates to the heat shields for all 2500's. When I bought mine in June of '06, it came with what appeared to be the final variant of this heat shield. But others have reported purchasing tractors much later than me, and getting them with an earlier heat shield configuration. I have no idea why this is the case, unless my dealer put on an updated heat shield when it was in for service last December, and I just didn't notice. What I can tell you is that I've had no issues with heat, but then I don't mow when the outside temp is over 80d anyway. I also removed the center louver cover as a precaution.
The third issue was with the strut mounts on the hood being cracked due to overtightening at the factory. This was resolved by most dealers by simply replacing the hood and installing them correctly. Cub at some point figured out why this was happening at the factory and corrected it there. I can't tell what time period this happened in because there's no easy way to know how long the tractors were sitting before this problem was noticed. My dealer never had any on his floor that had this problem, but then he's really good at going over the tractor's before delivering them or putting them on the floor.
So, in summary, the hood problems go back to all '06's models, and have been resolved. I don't know whether all '07's included all updates or not. I'm sure all '08's do though.