The hotel itself is okay, even though its location is bad. There is nothing around plus it is pretty far away from the railway station.
The room is good though we saw mould in several places.
I turned on my laptop and saw that there were several possible internet connections that required a username and password. I went down to the reception and asked for is and they handled me a piece of paper with the necessary information. The next day I realised that they had charged me 100 bath without letting me know that it wasn't free.
When we went down for breakfast and bell man stopped us and asked where we were going after the stay. We told him, that we needed to go to Koh Samui and he seemed very eager to help us. He could barely speak English, but we were informed, that we would be picked up at the hotel at 11:00 and dropped off at the boat that would be waiting for us and leave at 01:00pm. Everything sounded really nice, until we were dropped at the most random place 25 mins away from the hotel without any information. The man who worked here was the most arrogant and rude man we have ever experienced. I was furied when he told me we had to wait 2,5 hours at this rotten place before anything was going to happen.
NEVER MAKE ARRANGEMENTS WITH THESE PEOPLE.

After a long drive from Bangkok and as it was getting close to dusk the Diamond Plaza is the first "land mark" hotel as you enter Suratthani

The hotel was full with a local government conference and what could have been a pre selection meeting for Miss Thailand World - very, very busy - interesting mix of local folk!!
Reception staff were friendly and efficient and took the time to show us two rooms during a busy period.
The baby's cot arrived within 10min of check in and was clean.

The room was comfortable and clean the bathroom was larger than usual and had a separate shower.
The condition of the public areas was noticeably not up to standard - dirty windows, rubbish not cleaned up. This really detracted from what could have given us a much more favourable impression.

Operating only 2 out of the 4 lifts during a peak periods was a false economy

The "find" of the stay was the Salanchon (Sp?) restaurant
Located at the the back of the hotel (about 10min walk over the bridge) The local menu items were different, delicious and very cheap.

The "faux pas" of the stay was the breakfast a the hotel.
As one of the Thai conference delegates who shared the same table filled with plates and remnants of the previous guests on a fithly table cloth said to us...... " They call this the Khai Muk (translated means Peal) restaurant but it's more like the Khee Nok (translated means bird poop)
Rates as the worst managed breakfast, food and service wise, we've ever experienced.

Ok,
this hotel is in Surat.
So if you are driving to Koh Samui, this is a good hotel to stay on the mainland if you have to overnight before you catch the ferry to Samui.
1100 bht a night, huge clean rooms
Typical Thai Hotel.
Breakfast typical Local Thai Hotel, caters for the Thai's mainly, though there was some western food.
This was ok.
Hotel was located about 1 km from the turn off the highway into Surat township.
Again, typical Thai hotel, good transit, good value for money.
Would recommended

Reasonably clean, basic breakfast but OK if nothing more than reasonable 2-3 star standard is expected. Large hotel convenient for overnight stay and onward travel to Koh Samui in the morning. Rooms acceptable, but they show typical "wearing" marks like most hotels owned and operated by Thais. Investment in renewal and refurbishment only happens if inevitable - so potentially a very nice hotel if the owners would not mind to invest a bit in maintenance. Restaurant OK for Thai dinner. Thais get lower rates than foreigners if they walk in for a room - about 1,000 Baht for a double room including breakfast is what you should get...