I did the 10-day Alaskan cruise out of San Francisco on the Regal last year. Alaska was beautiful and I'm glad I went, but the Regal was my least favorite ship so far and I probably would hesitate to sail her again if other ships were available. I don't think there was anything really wrong with the ship, it just wasn't the right one for my tastes. Here's my observations comparing the Regal to my recent cruises on Sapphire and Dawn:
1) The inside cabin that I had on the Regal was comparable to the inside cabins that I had on Sapphire and Dawn.
2) Entertainment options were not as good as on the Sapphire or the Dawn. There just didn't seem to be very much going on, especially in the evenings.
3) Dining options were way worse than on Sapphire and Dawn. The buffet was much smaller with fewer options. Also, on the Regal, the buffet switched to just sandwiches everyday at around 2pm and to desserts only each evening at about 10pm, whereas on Sapphire and Dawn the buffet had a variety of real food 24 hours a day. Regal does not have an Anytime dining option, which was a big deal for my family since we dislike traditional dining.
4) Smoking is allowed in all cabins on all three ships. Smoking is also allowed on all three ships on one side of all outside decks and in designated areas of all bars and lounges and in all areas of the casino. Smoking is not allowed in the showroom or dining rooms. My mom is a heavy smoker, so I am quite used to cigarette smoke and I am not bothered by it at all, therefore, I cannot say whether the smoke on the Regal was worse than the other ships. It is just not something that I notice.
5) If you have children, be aware that the kid's camp on the Regal is very poorly located. It is at the very top of the ship and the only way to get to it is through an outside corridor and up an outside staircase that gets VERY windy. In inclement weather (as you will often see in Alaska), getting the children to/from the kid's camp can be very challenging. The camp had to actually close the entire last day due to poor weather.
I have read many reviews that said the Regal was the reviewer's favorite ship. For me, it was my least favorite. I think it is all very subjective. It just depends on what you're looking for in a cruise and your own personal preferences. For me, I think I would be better off sticking to the newer, larger ships.