I found very few reviews for Gate 1 Travel and the Monarch Empress traveling the Danube so I thought I would post a quick summary. Marigold252's review in post #2409882 ("Gate 1 17 Day Danube River Cruise with Warsaw, Krakow, Budapest & Prague") on this forum has some fairly detailed additional information.
This was our first river cruise and most of our tour experience has been with various Rick Steves' small group land tours - so our observations about this river cruise come from that perspective.
Gate 1 Travel - Their tag line seems to say it all... "See More of the World for Less". I certainly was unfamiliar with them but many of our fellow cruisers had done numerous land tours with them over the course of 5 - 10 years. They seem pretty well established but have a low profile compared to some of the other river cruise lines. When I compare the quality of the ship, food, service, and experience compared to the many other cruise lines I researched, we certainly felt that it was great value for money.
Cabins and Suites are compact on these river cruise lines -- yet I'm a big guy and didn't feel particularly cramped. The extra space in the 210 sq ft suite (vs 170 sq ft for a standard cabin I believe) was given over to a compact but comfortable seating area at the foot of the bed and a more spacious bathroom hosting a double sink and more counter space. Because this is a new ship, LED lighting, plumbing, and heat/AC worked flawlessly and we found no problem storing our clothes or other items. The outer wall is completely given over to a glass wall/french balcony with gorgeous view going by.
BUT... in hind sight I'm not sure that going with the larger suite was worth it... nor paying the up-charge for being on the upper-most deck:
a) With all of the optional excursions that we signed up for, we just found that we were rarely in our cabin unless we were sleeping. We used the nice seating area maybe twice in the entire time.
b) Because we were traveling in September, we found that the weather was typically too cool to leave the french balcony doors open... so we were often in the forward lounge looking at the view. Again... another reason we didn't take full advantage of the room.
c) On the Monarch Empress, I think all of the cabins on the top and middle floors/levels have french balconies regardless of being either a larger suite or smaller cabin... so it MIGHT make sense to just consider the smaller cabin.