I did three road Sportives last year, prior to this i'd never done one;
March (Cheshire Cat, taking in Mow Cop, Gun hill etc) This had about 3,000 participants and was great, all levels from the serious racer to the beginner who maybe set this as their goal to lose weight. Great weather (luckily) and great views and a route i would never had cycled as i'd just not know about it. I did the middle distance which for last year was 76 miles, 5k feet ascent. I didn't want to sign up on my own as like you id never done one before so roped my cousin in and once we started all the nerves etc had gone. It's not a race, let the racers go off and do their thing, we just soaked up the atmosphere and had a great day out with like minded individuals. Well organised and a great route.
May (Tour of the Peaks, taking in Cat and Fiddle, Winnats, and such other delights
). This had roughly half the participants of the CC and was a bit more hardcore in the participants, but again never really felt out of our depth. I signed up for this on my own but my cousin enjoyed the CC that much that he also signed and we went round together again. My cousin doesn't really like going up hills but he thoroughly enjoyed the route, scenery, atmosphere etc and we had an amazing day. It was also the hottest of the year which made a tough route tougher going. We went for the middle distance again which was 65 mile, 7k feet ascent.
September (White Peak, taking in just loads of hills in the south peaks). We signed up together again but my cousin twisted his ankle so didn't come along for this one. I therefore did this on my own. This had a similar number of participants than the TOTP but as I'd opted for the longer route which was 84 miles, 9k feet ascent there was definitely an increase in the ability of participants, many lean racing snakes, but again never really felt totally out of my depth and enjoyed it as much as i could. Weather was blustery and cold but again the route was amazing. As i was on my own i soon found a few other people in the same boat at a similar level so we rode along chatting. This was a great experience but i had some form of food poisoning that seemed to kick in just after the long route/short route split point and i just couldn't eat or really drink anything. I believe it was food poisoning from the night before and as i couldn't take in much if any substance i bonked with 15 miles to go, this was just hell for those last 15, i was so tempted to jump on the broom wagon when it went past
Overall i personally like sportives and I don't treat them as races as some people do. For me the challenge is the distance and trying to maintain my average over that distance. I probably average 17 mph over 30 miles, depending on the ascent - obviously drops as the ascending goes up. So i try and say do a 60 to 80 mile sportive but try to maintain my 30 miles average. For some people they are doing the 100 miles+ every weekend and it shows on a sportive but i am never going to be at that level, now too old and have too little time. If it wasn't for my cousin coming with me then i would not have done one but now i would happily sign up for one on my own and just go out at my own pace, enjoy the route and soak up the atmosphere. You also soon get used to riding in a group although from the Sportives i have done there really isnt that much group riding and it all blows apart anyway once you hit a climb which is great, just like on one of the grand tours