I tend to think the reviews make it sound worse than it is. But I do think having expectations correct about what you're going to get before going in is also kinda important. I haven't been on Insignia, but have been on two of the other R class ships Oceania has. Now, that said, if you've been doing Regent, I suspect it's going to be a step down from what you experience there.

It's an R class ship, so it's one of the older ones in their fleet. Personally, I've always kinda liked the R class ships (I have a lot of days on them between Princess and Oceania). That said, I've generally been in the lower end cabins on these ships, not the higher ones outside of one Princess cruise. Anything below the PH category has quite frankly the smallest showers I've ever seen on a cruise ship (and I recall them being larger when Princess had R class ships). PH and above don't have this issue.

In general, I've found the service levels to be pretty good for what's really just a somewhat upper level mass market cruise line. It's not as all-inclusive as something like Regent is (not sure where Viking falls in), and depending on what promotion you book under, you may have no alcohol included, or beer and wine at meals included (they've seemed to move away from this lately though).

Dining is always the subjective one. Oceania bills itself as the finest cuisine at sea, a statement that I'd probably go so far as say is laughable. I'd say the main dining room meals are "ok to good", but not really anything I'd write home about. Honestly, I'd say often I'd consider the meals to be about the same level as any other mass market line like Princess or Celebrity - maybe just slightly an edge over those? But not enough to brag about. The included specialty restaurants definitely were better, although you get limited visits for those (I do think higher cabin categories get more but no sure?). I will say that I do feel they do a pretty good job of dealing with allergies, and I'd consider them a significant step above in that over most other lines I've cruised with. But I'd also say that of the cruise lines that I've been on, I'd rate Windstar as higher than Oceania so far. (They do have the advantage of having smaller ships to cook for, and I feel it really shows).

Ultimately though, I do think a lot has to do with what your expectations are. As someone that's largely travelled mass market lines (generally Princess, Celebrity, RC, some Windstar), I'd probably say Oceania for a lot of things is a small step over Princess and Celebrity, but I also don't think it's as big of a step as they might think they are. I definitely wouldn't call them a luxury cruise line, more in that grey area between mass market and luxury. (That said, I think some of their pricing lately starting to get out of line with the experience on the ship. I've been looking at a couple of Christmas cruises this year, one Oceania, one Regent, with very similar routes, and the pricing is more or less identical, which given the lesser included items on Oceania I find their pricing for that cruise to be on the high side.) If you're someone that's largely experienced luxury lines, I suspect it'll feel like a step down, especially on the R class ships.