Generally avoid paid inspection trips. You can pretty well guarantee that the sales techniques will be used and many people far more astute than I, have ended up signing on the dotted line after a sangria-soaked lunch and then lived to regret it. In addition, you will ultimately end up paying for your "paid for" inspection trip through higher commission rates when you come to purchase.
Take the trouble of planning and making your own travel and accommodation arrangements. This way you are free to see a number of estate agents, and if you don´t like them or what they have to offer you can break away and start anew with someone else. Also, importantly you can plan some free time to visit the local attractions so that even if you do not buy a property you will have had something of a holiday.
If you are on a paid for inspection trip you will only get to meet the people the estate agent or developer wants you to meet. You might be wined and dined but are you getting to hear the nitty, gritty from previous customers?
When you organise your own trip and you find something you like you can spend time talking to the Brits who are already in the area. Any estate agent or property developer worth his salt will positively encourage you to talk to people who have bought from him on previous occasions. If that is not the case, then beware. Go to the local pubs and cafes and talk to the Brits, etc. in there. In this part of Spain there are so few Brits they stand out like sore thumbs. So if you see one walking around the village or town you are interested in, talk to them, chances are they live in the area and have the local knowledge you are seeking. A few words with someone with local knowledge are worth hundreds from the guy or gal who is trying to sell you something.