Well, just to prove how complicated the fares system is, the ticket office at Winchester found an even cheaper option! Off-Peak Day Return Portsmouth Stations to London Terminals at ^25.80 each plus the Victoria-Gatwick ^13.15 Anytime Single. I didn't think of buying a ticket for a longer-distance journey than I needed, but it was cheaper than the options I'd considered.
I think that Portsmouth - London is valid via Gatwick / you may not need the extra single.
I did wonder whether the extra single was necessary but, since the ticket office had come up with something cheaper than anything I had thought to try, I decided to assume they knew what they were doing and not argue. Either that or the ticket office didn't know whether GatEx would accept the ticket and hence played safe by adding the extra ticket.
I was surprised to see Portsmouth Harbour to London Waterloo via Eastleigh, Winchester & Basingstoke as an explicit mapped route (I know there is a direct train so it would be valid anyway).
Ah yes, the 'direct' (actually meaning 'through') train rule. I wonder if Portsmouth to London Victoria via Gatwick is a valid route or whether only the through train on that route is acceptable on the ticket. If that's the case, it would explain the extra ticket for my GatEx leg.
I hope you have a good trip BTW▸ Rhydgaled. In your OP▸ you mentioned the journey was today, but your follow up post was dated late this afternoon so maybe you're not doing it today.
Thanks, it was a good trip, at least as far as Gatwick (I don't know why*, but the 377 from there to Havant gave a really bumpy and lurchy ride, in contrast to the smooth ride on the 444 and 5-WES). I left Winchester on the 09:48 as planned and made it to Havant by 3pm.
* State of the track, fault with the unit or just a poor design of unit
FWIW▸ I am a fan of the 444s (the best air-con unlike the hothouse 166 I was on the other day; large windows; decent views from most seats; 2+2 layout; some tables) and I have fond memories of the 442s (particularly the "snug" part in the buffet car) so will be interested to hear your comparisons.
We're getting a bit off-topic for this section of the forum now, but I think it is hard to compare the train design itself, rather than the current interior fit (which can be changed at refurbishments). Both types were rather good, although I noticed that both types had quite wide pillars between windows (maybe I should have brought a tape measure to see which was wider). The window-size contest I think is won by the 5-WES. On both trains I think the interior was probably about as quiet as a mark3 coach on an IC125 set, but then I believe the coaches I boarded were trailers rather than motor coaches.
Regarding the current interior, on both trains we got a table bay well-aligned with the windows. The seats on modern trains tend to be unsatisfying, but in this case I think seats on the 5-WES were the more disapointing (but I think I still much prefered the unit to the 377). Note to seat designers: do not try to shape the seat to a person's body shape because pepole come in such a range of different sizes. I almost had a coach to myself on the GatEx, so I can't really comment on whether the luggage space was sufficient for an airport service (although I would say this provision was at least as much as most long-distance trains I have been on).
Regarding air-con, on the 377 in particular, I got the impression that the reduced power available on 3rd rail compared to OHLE meant the air-con was only really working when the train was coasting or stationary.