Both the one day tour and the longer tour were very good. The one day tour suffered from going to two very touristy spots with a long drive for one day. I think it would be more advisable to recommend closer experiences if possible for a one day trip. The guide Bom was excellent.
The guide for the longer trip Apple was very personable, friendly and helpful but we did feel at times that her English language skills were below par particularly in vocabulary and fluency in passing on information eg the history of an area. The content of the trip was on the whole very good though could have been a little more imaginative in some areas - we found that we consulted our Lonely Planet guidebook regularly eg for hints on good museums, other sites not on the itinerary. For instance the Sukhothai Museum turned out to be excellent for those interested in the local history , we also found a very interesting ceramic workshop which ran interesting tours . A range of additional things should be able to be suggested by a good guide. Sukhothai was a highlight for us particularly as the Loy Krathong festival was so brilliant with the illuminated historical site - a piece of info which was not included in our itinerary nor particularly emphasised by the guide. The Loy Krathong dinner which we attended in Chiang Mai hotel was fine though somewhat overrated (and artificial compared to Sukhothai event) . It would have be useful to know we were paying such a large amount for that particular event - the buffet food was definitely not memorable.
Also I may have missed it in info provided but it would be good to have some guidance on tipping (for guides/drivers) in Thailand as each country has been different approach to this.